I tested it and made some changes accordingly, I also went with VB because I didn't even have Perl installed on that server which is why nothing was passing. Took me a second to realize that.
Below parses a forwarded SNMP trap from Cisco Prime and then forwards it to NCM for Cisco Wireless Controller configuration change detection. Sadly, they don't send any user information with the trap. I have thought about creating another custom script to grab the user info from a login message but there's the slight possibility that someone could log into another controller and cause a false value for the change detection. I may investigate that later but for now I have what I want working.
Function Main()
strSource = VarRawMessageText
intStart = InStr(1, strSource, "var03_value=")
intEnd = InStr(1, strSource, " var04")
strIP = Mid(strSource, intStart + 12, intEnd - (intStart + 12))
VarCustom01 = strIP
Main = "OK"
End Function