Route Single IP over Ethernet, Route everything else wireless?

Question

Is it possible to have a Windows XP Home computer route all traffic, except that of a specific IP, MAC, Name, or IP Range, over one network interface (wireless), and route only the information destined for a specific computer over a different interface (Ethernet).

I don't want to bridge connections, as the second computer (wired) cannot have access to the wireless network, but I would like the first computer (wireless & wired) to have access to the wired computer. Security is really not an issue, so it doesn't have to be hacker-proof.

I would think this was not possible, except for these statements:
http://www.microsoft.com/windowsxp/expertzone/chats/transcripts/03october21.mspx
^ Search for "if you're joined to a domain"

http://www.hackerthreads.org/phpbb/viewtopic.php?t=1056&sid=1238dfe940ea8a60bd5883fda6fd215f
^Search for "When I attempt to ping"

Sorry I couldn't include the full text, but it was well over 1000 characters.

Answer 1

Simply create a network between the two PC's using either a cross-over CAT5 cable or a switch and standard cables. Give both machines IP addresses in a different subnet from the wireless connection (I assume the wireless card is connecting to your internet connection). Problem solved.
An example :- On the PC with both wireless and wired cards go to start /run and type in cmd and press return. In the command window type in ipconfig. The result should include the address of the wireless card. If this is, say 192.168.1.3, set up the wired card with 192.168.2.5 or similar, set the netmask to 255.255.255.0.
Set the other PC to 192.168.2.6, netmask 255.255.255.0. Set both PC's to the same workgroup name, maybe homenet, and then set up sharing on the machine you wish to provide files from, or both if you want them both to se each others files. If using XP / 2000 you will possibly need to set up identical usernames on each PC to prevent security problems. Using the same password for the same user on each PC really simplifies this.
In the example above I have shown allowed private network numbers. Your router will probably use one of the following ranges of addresses : 10.0.0.x (x represents the last number), 192.168.1.x, 192.168.2.x. As long as your other range has different third numbers in the 192.168.x.x series this will work.

Answer 2

Colinc gave you a good answer and it should work, one thing you may find is that on the machine that is "wired" you may need to enable NetBios on the eithernet adapter of both machines to get it to work correctly (I hate that but if it is not exposed to the world it isn't much of an issue).