Works Voip Phone Number At Home?

[Iggle Piggle]

Very techie question here:
At work I have a VOIP phone on my desk, I can log into any phone in the building and get calls to that particular phone.
My question is, when I work from home, is there any way I can get calls to my works desk number to ring a phone plugged into my computer?
The works IT dept. is stumped.
cheers techno bods!