How are you connecting? Serial, ethernet? I have a PC card for my laptop that has multiple serial ports. I can open SEL on one port and hyperterminal (or other terminal emulator) on another port. I'm guessing the same could work if you had a native ethernet port and then perhaps a USB to ethernet port if you wanted to go that way. If using RS-485, I believe you could daisy chain the connections and do it that way as well.
This was a common problem years ago when relay test sets used a serial port to communicate with test software and the relay did as well. I use the 2 serial port method when talking to an RTU and SEL often for metering checks / scaling. My PCMCIA card is sold by BB Electronics. I believe it was less than $100. SEL offers a serial to bluetooth device that you could also use on one of the relays and direct serial on the other.