Has anyone successfully used the FILERENAM Rule in a Migration Job? please?

as of the documentation : 

The file will be renamed in same manner as with FILEBKP, i.e. new filename will be <filename><seq.no>.bkp. If you also want it moved to another path/Directory, specify this in Rule Value.

after the datamigration job end we wouldlike to move the file and rename it.

Do enyone know how to put <seq.no> in the file name please?