Codingthewheel actually did a pretty intensive and in-depth series of blog posts about building a poker bot, you might want to check it out if you haven't alrea

Codingthewheel actually did a pretty intensive and in-depth series of blog posts about building a poker bot, you might want to check it out if you haven't already. IIRC covered things like communicating with the other processes, using Win32 APIs to scrape the text and controls of the poker client, how poker clients attempt to detect bots, etc.