How to create a DEFINATION for FILE, say /tmp/delta/bdw/data/xx_2007092_yy?

Hi Experts,

Am enhancing one Data Warehouse Extract Prog., , so I hv seen the paramener <b><i>p_file_name, say "Z_BDW_EXTRACT_TRANSFER_DEFINITION"</i></b> and its passing to FM <i><b>FILE_GET_NAME</b></i>, finally resulting in <i><b>"/tmp/delta/bdw/data/XX_20070929153330_YY"</b></i>. I hv seen the Txn <i><b>FILE</b></i> , so,

Now, I need to create a new DEFINATION

1) Pls. let me clarify that, How to get it done, step by step.

thanq.