how to drop last N characters from string?

    hi,

    It's relatively easy to get match by delimiting the start to the
    left, but how do you chop off N chracters from the right?

        VAR = "1234567890"

        :0
        * VAR 123\/.*
        {
            rest = $MATCH

            Now I want to cop off "90" from $rest ?
        }


    Also what's the procmail way to increment variable by N ?

    jari