you'd need to ensure you can connect out from work using port 3389 and if your using a router at home that the 3389 port is forwarded to your pc
might be that your work has a proxy server in place (definate no worky, you cant proxy RDC) and/or a firewall that could be only allowing ports 80, 81 and 21
first thing, do a tracert <ipaddress> from your work pc, the ip address being the net ip of your home pc, if it gets there then it might be feasible if it doesnt then give up
that aside i know if one of our staff asked me about connecting to their home pc from the office id tell them to go jump, its a serious security risk and i cant see any company going for it, if we caught someone somehow doing they would be fired for gross misconduct, keep this in mind because if they have logs of you doing this on their firewall they probably can fire you on the basis you could be copy/pasting customer information to your home pc, at best if your messing around just browsing the net from home your still not doing the job your paid for