SetWindowsHookEx - Controlling other process?

[teleplayr]

Hey, all. I'm trying to hook another GUI process so I can alter the data in some edit boxes.

I have the window handle of the app, and i have the PID of the app, retrieved with

GetWindowThreadProcessId();

The problm I have is, SetWindowsHookEx() wants a Thread ID, not a process ID. In other words, this code fails with error 87, BAD_PARAM:

GetWindowThreadProcessId(hDlg, &pid);
sg_hHook = SetWindowsHookEx(WH_CALLWNDPROC, (HOOKPROC)pHookProc, hRes, pid);

if (sg_hHook == NULL)
{ 
   // Process error
}

But this code passes:

sg_hHook = SetWindowsHookEx(WH_CALLWNDPROC, (HOOKPROC)pHookProc, hRes, GetCurrentThreadId());

if (sg_hHook == NULL)
{
   // Process error
}

But then my app just hooks itself

So, is there a way to convert that PID iinto a Thread ID? Or, is there a better way to meddle with another applications edit controls?

Thanks,

-Joe