> Thanks, but I mean the index as produced by makeindex. You can change the font used by makeindex in LyX simply by dragging across the "Index" button that you inserted and change the font. This will apply to the font change to every item in the index
For more sophisticated changes, I wrote a wrapper to beautify the output makeindex, and integrated it into my personal version of http://wiki.lyx.org/Tools/LyX-GrammarChecker If you are interested, I can mail it to you -- John C. McCabe-Dansted Master's Student