GetSpecialCodeValue
function GetSpecialCodeValue (const Key : TKey; const Code : TCode) : LongInt;
GetSpecialCodeValue returns the value that was used to create the Code.
Key must be the same key that was used to create the code or the code is considered invalid. If the code is invalid, 0 is returned.
This routine is defined in the OnGuard unit. (as of 1.15 this routine has been moved to the OgUtil unit)