FormApI and Replicant

AKB

Hi,
In my DCT there is a replicant which consist of two fields. The first field is a browse filed and the second is text. The second filed needs to be filled automatically based on the file selected in the browse field.
This functionality is easy to implement when there is no replicant but if I want to have the functionality in a replicant how do we do it.
Thanks a lot,