file extension does not matter, windows nor unix  ...you can give extension unmap_dev.sanjit and it will work just fine.
I am trying to ummap few symm devices using SYMCLI in a windows machine using the following commands   symconfigure commit -sid XXXX -file unmap_dev.cmd Where unmap_dev.cmd contains:unmap dev 020:024 from dir ALL:ALL;  Can I use a .txt file insted of .cmd file here? How to create a .cmd file in windows? Have never used SYMCLI in windows before..... appreciate your early reply.
Command file for symconfigure