how to set up COM 1 on a Texicom Premier 48?

I have been trying to set up my PC to work on the Wintex software but will only work on COM 2. As COM 2 is already used for the GSM signalling( and this also will only work on COM2) I seem to be stuck. I have followed the set up and have "nothing fitted" in the COM1 set up. Any advice would be appreciated.