Need a Help

Hi,

       I need small help.I have 3 type of files,files will come as per the business needs.
       files look like these
                     realage_campaign1_20080201132132.txt
                     dogage_campaign2_20080201132132.txt                      
                     catage_campaign3_20080201132132.txt

Based on the type of file, i need to extract in two methods..
   1. Site ID will be derived based on first part of the file name

                      Site Name = realage  Site ID = 1
                      Site Name = dogage  Site ID = 2
                      Site Name = catage   Site ID = 3
    2. List Name will be based on 2nd part of the file name

                     Example : For file realage_campaign1_20080201132132.txt                                            
                                                   List Name = campaign1

Can you please help me to write the code to extract the above mentioned logic.

Thanks in advance