Hi,
Might be possible by using RFC. But you may face issues.
Because enhancement code is based on ecc fields. those won't be compatible at bw side.
Actually why you need to ecc details at bw side?
All below points need to check source system side.
1. You can check at CMOD, by using standard exits. or
at SE38. ZXRSAU01/02/03 depend on data source type you can use program and search for your data source you may know the code if your data source was enhanced by using cmod.
2.Data source extract structure name you can get from source system, RSA6, double click on your data source, open next screen you may see it. There is no specific name for enhancement. but all enhancement components under RSAP0001.
3. Yes, you can check program ZXRSAU01 - transaction data source, once you open thi program, you can search for your data source, you may see the relevant code for your data source enhancement.
As my guess your data source is transaction data source.
Thanks