I solved my TAPI-problem using C#s excellent COM binding – BUT my solution does not work reliable. Recently I discovered this knowledge article – M$ recomends against using TAPI from managed code, which made me searching for another solution to invoke calls from a python script. TAPI handling is really really ugly if you do not want to dive into Windows COM-programming and using the older C-interface also is the opposit of fun.
TAPI SUCKS!