Today I changed the chm help generation of fpspreadsheet from Doc-O-matic to pasdoc. I can say: Excellent work in pasdoc!
Initially I created the chm file with the MS HMTL Help Workshop - which was quite easy because pasdoc creates the required hhp project file with everything required: simply load the hhp file into the workshop and click the compile button.
Then, motivated by this thread, I built myself a chmcmd binary from both FPC trunk and FPC 3.2. And - surprise - each version can create the chm file correctly. There are a bunch of warnings and even error messages, maybe because I did not include all fpspreadsheet files in the help project, and thus there could be some links pointing into nowhere. But the chm file can be opened, and it seems to be working correctly.
I should mention, however, that chmcmd still has the old problem that it must be started from the folder with the hhp file.