Hi,
I think this is quite simple task, I can finish it over one night. This is some info for your consideration:
1/ It's better if there is IIS on the server, developing a .NET webservice is fast. Otherwise I have to write the server part all over, take more time and cost.
2/ DHCP problem can be solved if you have access to the DHCP server (router), I can help with that. Anyway I can make a scan function on the client program to search thru local network for the server.
3/ I can help with any setup via teamviewer sessions.
Hire me!