[Orion] ORION and MixW and USB to serial port adapter?

[dbp at tds.net]

Hi-
 I have an ORION, using it with MixW 2.15, and  Toshiba lap top running ME. There is no serial port, but two USB ports.
 A Belkin USB port to Serial port adapter was purchased. Computer see's the adapter. 
 It will give me PTT for Transmit of CW or PSK but, I cannot get MixW to work to change the frequency of the ORION when clicking on a DX spot in MixW. All combinations of DTR and RTS have been tried. Serial port is set to 57.6, 8, N, 1.
 What am I missing?

73 de Dave