urgency: how to add additional fields to XML and tranfer to MDMcatalog

Dear experts:

I have realized the standar process for contract to mdm. when contract is released, the MDM catalog be updated automatically.

but I still have two requirement.

1. In standar process, the product category and short description these two fields are not in XML and can not transfer to MDM.

2. I have some user-defined fields in header in contract . I hope these CUFs can be added to XML and transfer to mdm ,

please tell me how to do or give me some document in SRM. (srm 7.0 MDM-Catalog 3.0 , MDM 7.1).

thanks in advance.

Jesse.