Returns the value of the BLF_CUSTOMEXT flag. Represents the value of the 'Use Custom Extension' checkbox.
IsCustomExtensionEnabled(pBlackIceDEVMODE As Long) As Boolean
Input value - handle to the BlackIceDEVMODE
Return value - TRUE if Use Custom Extension is used, otherwise FALSE
NOTE: For 32-bit applications , use pBlackIceDEVMODE as Integer, instead of Long.