Heres some example code for ya using the winzip command line support....

Code:
$null = SetOption ("NoVarsInStrings","On")
$null = SetOption ("Explicit","On")

Dim $backupfile,$backupto,$wzzip,$datestamp,$MonthNo,$MDayNo

$backupfile = "C:\temptest.txt"
$backupto = "C:\Backups"
$wzzip = ReadValue("HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\wzzip.exe","")

If @MDayNo = "1"
   If Len(@MonthNo) = 1
      $MonthNo = "0"+@MonthNo
   Else
      $MonthNo = @MonthNo
   Endif
   If Len(@MDayNo) = 1
      $MDayNo = "0"+@MDayNo
   Else
      $MDayNo = @MDayNo
   Endif
   $datestamp = ""+@Year+"-"+$MonthNo+"-"+$MDayNo
   Shell '%comspec% /c "'+$wzzip+'" -rp '+$backupto+'\'+$datestamp+'.zip '+$backupfile
Endif