How to get the right memory address

[efkefk]

Hello,

I use a callback function from a "non managed" dll. It looks like this:
public static void TheCallback(System.Int32 MemoryPtr, Form1 form)

The parameter "form" is ok because I am able to do some action like:
form.ExistingLabelInForm1.Text = "It is ok";

But the memory at the address pointed by "MemoryPtr" does not show the correct data that the dll is supposed to send.

I would like to know how to recover the memory data from the dll ?

Remark: when I do the same job with Visual c++ program, the memory data are correct.

Regards.