Short version - You're going to need a router.
Slightly longer version. When you say "network" I'm guessing you mean subnet, so the guests might have IP addresses like 10.1.1.* and your PC might have an IP like 10.2.2.*. Your issue is that they both need a device to act as a gateway to get them to the internet. That device device, a router, has to have a similar address. I'm not aware of any SOHO routers that will take multiple subnets but there are almost certainly some available.
Some quick Googling turned up mentions of a Cisco 806 that will do but is a "couple hundred bucks".
Another suggestions was to take two standard Netgear, D-Link, etc home router and hang one off the other. That should work and might be the easiest solution, put your PC behind the second router so that it helps protect you from the guest network.
You can also make a PC act as a router but the nested approach is probably the simplest and as home routers aren't too pricey is probably the way to go.
i already have 2 subnets the thing is i dont want my guests on my private WLAN – Chaos – 2013-05-21T14:58:38.233
I'm not understanding the network then. Are you saying you want two wireless networks? That means two SSIDs which some equipment won't do. You might trying adding a simple diagram of the current network and elaborating on what you're trying to accomplish. From what I gather you just want your PC separated from the guest network. – Dave Noonan – 2013-05-21T15:11:04.947
thanks for the tipp about the diagram i was overcomplicating things since i use a access point to share the internet with my guest i could just use the 2 access points to make another bridge so i have 2 bridges 1 hidden with the private network and another just for the guest network – Chaos – 2013-05-22T07:33:52.267