I found this page (in deutsch) which seems to document an otherwise undocumented function, namely GetPermLayers from aphelp.dll.

I don't know where they got it, but seems a realistic definition. 

Hope it helps. And thanks for your development effort, go on this way! :D 

P.S. It' in delphi, there's a "var" keyword, which should means (from google, I'm not a delphist) an optional argument. IDA PRO gives error when given the last two args. Hope you can figure out where's the problem