Connecting arduino to PC through Serial1 instead of USB

Ladies and Gents,

I have searched under and over this forum for the specific topic of discussion and cannot find a solution.
Basically, I want to use a MAX232 chip and a DB9 connector to connect to a PC and have the module (AKA Arduino) recognized by windows 7 so that I can assign a COM port. Note, I do NOT want to use the USB port because of backward compatability with older windows and PC hardware (DB9 ports).

My project consists of communicating to an SDR (Software Defined Radio Software + virtual COM Port program) via the arduino, taking the frequency and moving a stepper motor based upon a look-up table of step counts.

Can someone kindly help me with this or at least tell me how to get on the right track with some tid bits of code or examples.

FYI, I have not begun to write code for this project so no code available but, I do have an understanding of C++.

Thanks in advance

You can still get an early Serial Arduino bare board from Mouser
Scroll way down here to see a completed card.

Crossroads, :slightly_frowning_face:

Thats not an option because I am developing my own PCB with the max232CPE chip integrated. Thats why USB is not an option because it does not exist. If you can picture just the 328 chip soldered to a PCB or socketed, this what my project will look like.

Again, I need a software option that recognizes the chip as an entity.