That actually won't work correctly as a Kiwi script if you put the wscript.echo in it. I have that in my script as a section to write a debug file, I changed it to an echo statement to simplify it for you but Kiwi won't show that output.
All you need is this:
Function Main()
CleanMsg = Fields.VarCleanMessageText
arrSplits = split(CleanMsg, ",")
Fields.VarCleanMessageText = arrsplits(2) & VbCrLf & arrSplits(7) & VbCrLf & arrSplits(8) & VbCrLf & arrSplits(12)
Main = "OK"
End Function