A Batch or VB Script to see ifa key exist and add a DWORD Value to REGISTRY

I would like to script the below Registry  Change  (ADD) to be deployed via SCCM - if possible,
                            I want to check if "HKEY_LOCAL_MACHINE\SOFTWARE\Novell\Zenworks\ZenLgn" exist
                            then  want to add the following DWORDS Value

If the Key does is NOT Present, I want the script NOT TO MAKE  any Changes.


[HKEY_LOCAL_MACHINE\SOFTWARE\Novell\Zenworks\ZenLgn]
"DisablePassiveModeLogin"=dword:00000001
 "DisablePassiveModeLoginPrompt"=dword:00000001 -


Any help is Greatly Appreciated!!