I have a spreadsheet with some hidden cells in each sheet containing certain
bits of information I don't want the user to see, including the help topic ID
for that sheet.

I would like to be able to read a CHM file from a VBA function in order to
check that the help topic IDs set up in the spreadsheet actually exist in the
associated help file. I've tried googling for this, but all I get are entries
for applications like RoboHelp.

Does anybody here have any links that I can use to learn how to do this?