Pointers In Delphi

Here's the situation. I have a dll I'm making in delphi, and I need to pass an address in memory to it (a backbuffer address to be precise). The external program can only pass in variables, so I need to know how to take the address stored in the variable, and assign it to the pointer. My initial thought was to simply do this... ptr := variable As you would do ptr := @variable If you were pointing to that variable, but that doesn't work. Are there any functions or other methods by which I can do this? Cheers for your help in advance.