With the help of this forum i already got far in solving my problem.
I have created a FM for Delta Extraction, have changed the Table ROOSOURCE to use the extended interface EXMETHOD = 'F1', and now init and full is working. The problem is that delta is not deliviering data to bw. The strange facts are that my FM is working, and i activated the testdelta ROOSOURCE-READONLY and checked in RSA3 and it's delivering data. I have tried some Delta Types DELTA and NEWE in ROOSOURCE. I have debugged what r/3 is doing after my FM but i don't get a real clue out of this. I will investigate this further. But i believe someone of you has done this already and give me a quick clue what to look for.
(I think it's kind of strange that all this is not supported from sap itself. I mean change tables and this stuff, ok i like it but i don't have full insight in this now. )
If you need further details please ask. Maybe i could use generic delta but to be honest i want to know how all this is working and have "full" control.
Thanks for the respons.