I recently started using AutoIt for some development project and I've found & enhanced the OOoCOM_UDF.au3 file to work in a way that is compatible with the standard excel library.
modified entries include:
The listed functions are now interchangeable between Microsoft Office (Excel) and Open Office (Calc). I've also improved the working of these functions to call the "correct" API's.
In my search I've found that the OpenOffice site: http://api.openoffice.org/ was very useful.
Please report back with your findings.
All the best,