Either you'll need to add a DNS entry to a local DNS server or if it's only a few PCs and you don't already have a local DNS then adding an entry to the hosts file on every PC that you wish to access it from. I can't give you the details OTTOMH but you should find enough info via google.

There is also the WINS service (how Windows PCs normally access each other by name on a small network) but in my experience that is unreliable, especially when used with a consumer grade router. But in fairness I haven't used it for a long time so perhaps things have improved.