Error traping in DTS

I am using a DTS for my purpose and I am calling that DTS execution in a stored procedure(using master..xp_cmdshell dtsrun/F).I like to store the error meassage or error description in the Stored Procedure if it fails due to any reason.How can I do that?call the dtsrun also with /L<log file path >|||Will you kindly give me a brief of that please?|||dtsrun gets some arguments the /L <file path > switch "tells" dtsrun where to log it executed steps results
for more info search books online for "dtsrun Utility" there you can find all info about dtsrun.