It's possible, but is definately not a trivial task. The easy part is using a Winsock control to connect to the printer via TCP. The hard part is figuring out how to format the output. If the printers are post-script printers, that might not be too hard. Just create a local printer that prints to PS files (HP driver would be a good bet.) and grab the output file. Then write it to the socket that you've opened along with the appropriate control codes from the LPR specification. If you aren't comfortable with doing your own raw socket writes, I'd try to find appropriate printer drivers to use and let Windows do the work. You could also look into using IPP or print through HTTP if you will be using IIS. This page has more infomation:

http://www.microsoft.com/technet/pro.../contchov.mspx