extremely simple list question

    Mar 03 2008 | 10:08 pm
    Hi all
    This is a extremely simple question about changing a single value in a list in a message object.
    How know how to easily fetch any value with zl nth.
    But I haven't figured out how to keep a list and change only one desired figure at a time keeping the rest of the list unchanged.
    Of course i know it would involve the $1. But having multiple combinations, I haven't figure out this probably more than obvious one.
    Thanks to all