FKV and UD field

Hi there

I am customising the DMR Processing screen- new ud fields are being added. Two of which are Name and EMail -i can link the name to the userfile.Name binding and that works fine- what i would like to do is on selection of the user name, that the userfile.email is retrieved and stored in the Email field.

I thought i could use FKV for this but ud field is not listed to create the fkv…

Any ideas?