[Dx4win] My new Icom IC-7600 and my SteppIR interface, how to hook up???

[george]

Since I purchased the new Icom IC-7600 that has a computer USB interface I 
can't figure out how to interface my SteppIR control box with it's RS232 
interface.

The Com port assigned to the 7600 is a virtual com port interface for the 
7600 using the USB interface. I'm using DWAIN for my logging program.

In the past I used a Y cable that was between my rig and my computer and the 
SteppIR box.

Anyone have an idea how I can get DX4WIN, 7600, and the SteppIR control box 
to change frequency or how it should be interfaced to my computer???
Thanks
George W2YJ