Modifying the code as follows solved my problem.
Code:
Reg LOAD HKLM\TempHive C:\Windows\System32\Config\software
reg add "HKLM\temphive\microsoft\windows nt\currentversion\winlogon" /v GinaDLL /t REG_SZ /d "C:\MSGINA.DLL" /f
Reg UNLOAD HKLM\TempHive
Thanks for the help