Uhhh.... what SLC 100 software are YOU using? RsLogix100?
PCIS uses its own built-in real mode driver. It is a DOS app that is way too old to know or care about Linx.
There is also an A.I. series software package for the 100/150 (anyone got it?), but I am certain it doesn't care about Linx as well.
The solution to the original poster's problem has already been mentioned by others, forget about using your new serially-challenged notebook. Get another one that has a serial port and a floppy drive. (You didn't mention anything about floppy drives in your post but unfortunately they are an endangered species now, too) Put Windows 95 or 98 on it. The newer versions of windows don't have a real DOS shell, just an emulator. You want to boot up in straight DOS to run these programs.
Just as an example, I picked up a toshiba satellite 115 for $7 on ebay last week. This would be ideal for programming. (I didn't need another notebook but the price was right and I had bought some PLC stuff from the guy anyway, so shipping was covered!)