Two rs232 devices in one

Hi everyone!

I have two devices connected via RS232(COM, Serial) ports, /dev/ttyS1 and /dev/ttyS2. They simply sends a short string (8 chars). And I have a Windows program running under Wine that can use only one rs232 device. If I make symbolic link “com1” in wine’s dosdevices to ttyS1 or ttyS2 they both work correctly. But my program can use only one device.
How can I merge two com devices in one? Is it possible? I try this:

mkfifo pipe1
cat /dev/ttyS1 > pipe1
cat /dev/ttyS2 > pipe1
cat pipe1

After this, when I send data to /dev/ttyS1 and /dev/ttyS2, it appear in terminal. But when I make symlink to pipe1 in wine, they both don’t work. Any ideas?

Thanks for help, sorry for my english =)