Determining File Name in Info Package under External Data

Determining File Name in Info Package under External Data

I am on SAP BW 3.0. A System is sending a flat file every few days

With a date time stamp, e.g., d:\loaddar\file_20080212_122300.csv

I know in Info Package one can create routine under external data to determine the file name. I have seen

Examples where people determine file name based on date. Since my file has a time stamp, what code I write a to pick the file. Is there a way to read one or more files and

Determine file name.

I am new to SAP BW and ABAP. However, I have lot of experience with Oracle and Java.

Can someone point me how this will be done. I am looking for some sample code as well.

Thanks in advance. I will really appreciate your help.