pointers with System::Call

[BoscoBilly]

Hi.
I am using the GetMacAddr sample provided by Brainsucker.
Getting the IP_ADAPTER_INFO structure vars the way he did it works fine - thanks Brainsucker!
However, I am trying to get a string var in that struct that needs to be accessed by pointer.
here are two lines: the 1st is the working stuff with my attempt to get the pointer I need; the 2nd is my non-working atempt to retrieve the value of that pointer that I need.

System::Call '*$4(i.r4,i,&t260.r5, &t132.r6, i.r7, l.r8,,,,,*i R1)'

System::Call '$R1->IpAddressList.IpAddress.String(t R2)'

At the end of the first line, var R1 is a pointer.
In the 2nd line, I try to get the string - it returns nothing.
Could someone pl explain what I am doing wrong here?
Thx.