You could do it with any programming language.
However, the program must be written specifically for the given forum, because each forum has a different way to login the user and to post an article. Therefore no general solution is possible. (Even if you would say what kind of a forum it is, you would have to modify the script to include the proper URL, the subforum you want to write to, etc.)
And if the forum uses captcha, that's too bad. A possible workaround for this could be if you log in from your laptop manually, and then your script does some automatic activity for 10 days, to avoid automatic logout for inactivity. But that's really wasteful.What about some out-of-the-box solution, such as: ask someone else to post the articles for you