choose from list (CFL) in the UDO

Dear Experts,

I have an UDO called work center routing. The work center routing consists of header and line.  I use resource master data for the UDO. I want to add CFL of

resource master data in my resource column of UDO line. How can i resolve it ? I am using SAP B1 9.1 PL05. Help please

Rgds,

Steve