With XP it should be possible. It was in Vista too, but not Win7 or later.
I use the d3dwindower and not DXWnd
Select the EAW he wants to run
Click the green triangle.
The box next to it will become red. That makes EAW the "active" emulation.
Minimise the windower but do not close it
When GameRanger runs his multiplayer should be in a window.
Clicking the green triangle is the thing that does not work in Windows 7 or 10. The box never becomes red, but it does in XP.
Maybe you can fly with us at GameRanger- just let us know