Lots of ways to skin this cat; depends on exactly what you want to do. From your question, it was not entirely clear to me what you were trying to achieve. One way to set a parameter inside a DTS package is to use a "Set Dynamic Properties" task to set the value of a global variable. Then use the global variable inside a Data Pump (use a '?' inside the SQL Query to place a parameter and finally associate the parameter(s) to the '?' by clicking on the "parameters" button underneath the SQL Query window.
Another way is to set a package level global variable from a separate DTS package (or from a VB Script) and then call the target DTS package. This is done sometimes when a loop mechanism is needed.
In either case, consult with www.sqldts.com and do a search using Google. You'll find quite a few other (and probably better) examples out there.
Set oWatchlistPackage = CreateObject("DTS.Package2")
oWatchlistPackage.GlobalVariables.Item("sFileName").Value = oRS("ORIG_FILE_NAME")
oWatchlistPackage.GlobalVariables.Item("iAgency").Value = oRS("AGENCY")
oWatchlistPackage.GlobalVariables.Item("sUserName").Value = oRS("MODIFIED_BY")
oWatchlistPackage.GlobalVariables.Item("iFileID").Value = oRS("FILE_ID")
Have you hugged your backup today?