How to set Security in Voucher Match program

Hi Guys
We are planning to provide a security group with ability to close partial paid POs. In order to do that, the value field OP (MAST, the field control processing of vouchers in OneWorld) must be 9 in the Voucher Match application P4314,. I tried row security on UDC table associated with this field ( Product Code 43, User defined code = VM and code=9), but row security only provide security based on one field( Not dependant).

The other option is that I can proceed with security on filed code in UDC table, but with this solution, the problem is that it will impact UDC values in other applications.
I would appreciate any suggestions.

Thanks

hey, we just went thru this last week in our system. checked with GSS, apparently we cant set any security to bar users from entering other options aside from the supposed '9' only. we can opt to control by doing a slight customization..... aside from that, cancelled qty doesnt populate in F4311 nor F43121.... which makes it difficult to track just exactly which was closed or not.