Recently (well, not that recently – I've been a bit remiss) someone asked for me to post some help for more advanced users who need an easier way to create an index in Word. Sorry for the delay, but here it is.
First of all, the Mark Index Entry dialog box is NOT one of the ways to speed up this process :) In this post, I'll give you my picks for the 2 ways to do this most efficiently ... using an AutoMark (concordance) file and creating and editing the index entry fields directly.
Option 1: Use a Concordance File (an AutoMark Index file)
The easiest way to create an index (and, in a long document, it's an ENORMOUS timesaver) is to create a concordance file. In the Index and Tables dialog box, this is referred to as the AutoMark Index file. A concordance file is just a simple, two-column table that lists the words to look for in the left column and the name of the index entry to mark them for in the right column. And, when I say 'simple table,' please take that literally. Some formatting will actually keep the concordance file from working properly – so just insert a default table and type in your text.
For step-by-step instructions on creating a concordance file, click here for a Word 2003 help entry (and click the option 'Automatically mark entries using a concordance file').
Once you have completed and saved your concordance file, close it and return to your main document to be indexed. Go to Insert, Reference, Index and Tables, Index, and click AutoMark. Select the file and click Open. Your document will be marked automatically. You can then just place your insertion point where you want the index to appear and return to the Index and Tables dialog box and generate your Index. (or create the INDEX field right on screen if you know how to do so -- if you don't, check out the fields post link referenced in the next part of this post for help).
Note: Once the index is generated, keep in mind that all the concordance file has done is to enable Word to automatically place index entry marks throughout the document. So, if you need to mark additional entries, change entry names, add subentries, you can do that directly through the index entry fields (discussed next).
Option 2: Create and edit the index entry field codes yourself
First, if you are not familiar with how to create and edit field codes directly on screen, read my earlier post Let's Talk About Fields, Baby – which is basically an advanced 'short course' in understanding and working with field codes. The rest of this post assumes you know the stuff in that one.
The Mark Index Entry dialog box is a bit cumbersome, because you have to type the information in each time (and a typo in the entry name will result in an entirely new entry instead of adding the marked content to the existing one). Personally, I find it much easier to create the fields directly – which only requires being familiar with the construction of the index entry field code and possible switches (customizations), so here goes:
XE is the name of the index entry field.
The structure is to put the entry name in quotes following the field code name. If you have sub-entries, each new sub-level is separate by a colon. So, for example, for an index entry about an index in the reference tools in Word, the field code might look like this (within field brackets, of course):
XE "Word:Reference:Index"
Which would result in an index entry that looked something like this if the index entry fields appear on pages 3 and 4 (depending upon the index format you select):

You can find the switches available to an index entry field by looking up XE Field Code in the Type a question for help box in Word – or by looking at the field code in the Field dialog box. But, here are the most common for quick reference:
\b – makes the page number appear bold in the index
\i – makes the page number appear in italics
\r – uses a bookmark (typed in quotes after the switch) for a page range reference instead of the page on which that the XE field code appears
\t – uses any text you put in quotes after this switch in place of the page number for that entry (such as 'See also ….')
A couple of examples …
XE "Word:Reference" \b \r "ref"
Would result in an index entry that looks something like this:

… assuming that the bookmark named 'ref' spanned the page range 3 – 5.
XE "Word:Reference" \i \t "See also Word, Fields"
Would result in an index entry that looks something like this:

Tip: Once you have created one XE field code (or used the Mark Index Entry dialog box to create one – which you can access with the shortcut Alt+Shift+X) – you can copy and edit the field code just like you do text.
By the way … the tips here will still work in Word 2007 – your index will just now be placed in a document part, as all reference tables are in 2007 – which is pretty cool new functionality (and will be addressed down the road, as I start blogging about Office 2007).
Happy Thursday everyone!