Dyneshwar,
You mentioned F110, which indicates that the file you intend to create is meant for Payments to Vendors/Customers which should be specific to Bank File Format.(SAP to Bank)
But the Program RFFOM100 is meant for uploading the file that we receive from the Bank into SAP once the Payment files are processed by the Bank. (Bank to SAP).
IMHO,developing a zprogram using REGUH/REGUP ( as it is F110) and other Master data tables for details such as Bank data,Vendor info,etc, to download the file as per the Bank specific file format to Application Server preferably encrypted is the best solution.You can ask the User to run this program manually or as a job at the end of the day or at regular intervals once they are done with F110 run.
K.Kiran.