I know you can change package variables, but I'd have to dig through to figure this one out.
I have an ActiveX script that worked in v7.0, that changed the connection string for a package. Basically, I did the following:
Set oPKG = CreateObject("DTS.Package")
oPKG.LoadFromSQLServer strServerName, , , 256, , , , strPackageName
For Each oConnection in oPKG.Connections
objTxtFile.writeline( " Old DS:" & oConnection.DataSource )
' if matches conneciton I want to change
If oConnection.Name = strPackageConn Then
oConnection.DataSource = objFileItem
strSourceFile = strSourcePath & "\" & objFileItem.Name
strDestFile = strProcessedFolder & "\" & objFileItem.Name
intError = oPKG.Execute
I would bet there is a way to grab the error file location from the object model of the package. You'd have to dig through BOL to see. A quick glance at the OLAP unleashed shows there is a .LogFileName property you can set.