On our servers with NetShield 4.5, the code as posted comes up with an empty product value. I changed the reg path as below, and it works OK. Just thought I would mention it if somebody wants to take a look.

code:
 CASE
       ;NS45
       KeyExist($hklms+'\Network Associates\TVD\Netshield NT\CurrentVersion')
       $datnum=SUBSTR(READVALUE($hklms+'\Network Associates\TVD\Netshield NT\CurrentVersion','szVirDefVer'),5,4)
       $engine=READVALUE($hklms+'\Network Associates\TVD\Netshield NT\CurrentVersion','szEngineVer')
       ;$product=READVALUE($hklms+'\Network Associates\TVD\VirusScan','szCurrentVersionNumber')
       $product=READVALUE($hklms+'\Network Associates\TVD\Netshield NT\CurrentVersion','szProductVer')