Code:
function SetPassword( $userID, $password, optional $computer )
    dim $objUser

    if not $computer $computer = "." endif

    $objUser = GetObject("WinNT://" + $computer + "/" + $userID + ",user")
    if @error    exit 1    endif

    ;-- Set the password for the account -- 
    $objUser.SetPassword( $Password )
    $objUser.SetInfo()
    If @error
        exit 2
    Else
        exit 0
    EndIf
endfunction
if you don't have the RenameUser tool, you could try this function.
_________________________
Christophe