Your problem then, is political, not technical.
You don't really say where the devices are located, but I'm assuming you want to leave your PC on at work, then go home, dial into your ISP, then PC Anywhere back into work. The problem is likely to be that many of the tcp connections are blocked as well, including the biggies: smtp, http, pop3, ssl, https, and in fact, you may be subject to Network Address Translation as well.
I would highly recommend that you approach a) your network admin or b) your management regarding your requirements to run PCAnywhere and establish a solution which satisfies your need to get your work done and your netadmin's desire for security.
There's a way to get it done!
Hope this helps -
Kent