Variable Substitution not working when using ABAP mapping

Hi all,

I am doing an IDoc to File scenario.

Due to some complex mapping requirements, i had to use ABAP mapping for IDoc to File ( IDoc : SHPMNT05)

There is also one more requirement where in i need to generate the receiver filename dynamically

i.e the filename is of the form :

GW-XYZ-DD/MM/YYYY.csv

Where

XYZ is the Shipment number (E1EDT20- TKNUM)

DD/MM/YYYY is the IDOC creation date in ECC (EDIDC-CREDAT)

so i used the variable substitution option in receiver file adapter.

But its not working.

Is there any limitation for using the variable Substitution, doesnt variable substitution work in case of ABAP mapping?

Regards,

Loveena.