|I'm not familiar enough with what it is you're trying to accomplish exactly - but I'd suggest taking a look at devcon (http://www.robvanderwoude.com/devcon.php). |
That might get you pointed in the right direction.
The other place I'd start (coming from managing triple the amount of POS terminals) would be to look for a registry entry that can be changed to modify the com port settings. It would make things infinity easier if that were the case.