Hi Pankaj,
there is very good blog for SC, you have to do same for RFX.
Please see.
Custom Field for SRM SC WebDynpro Application
http://scn.sap.com/docs/DOC-25692
You need to add the fields also in the structure:
INCL_EEW_PD_HEADER_CSF
is necessary to add the fields in both structures.
Then you need to go to:
Configure Field Control -> Configure Control for Fields on Header Level -> Metadata for Fields on Document Headers
And add a new entry for BUS2200 check "Field Visible" and "Field Enabled".
And that's all, with this the fields must appear. You don't need to add an append structure in other tables.
Hope this help you.
Best regards,
Rohit