I have a VB GUI talking to a DLL written in C++ and one of the C++ function requires a pointer to an integer. The program is called but the pointer is NULL.

(#1) How do I define an integer pointer in Visual Basic to pass to a C++ routine?

(#2) How do I make the pointer such that it is not null in Visual Basic?

From VB, the declaration of the C++ method must be

... byref myValue as Long, ...

that says that myValue must be passed as reference (internally VB will pass the pointer of the value) When calling it:

dim myVal as Long
...(... , myval, ....)

Hope it's clear enough

PS you did not specify if the integer was a VB (16 bits) or C++ (32 bits) In my example I presumed was a int32.
Marco