Question regarding spoofing

There exists programs such as synner.pl or Xxpoof where one can send spoofed source packets to a target IP address. However, this is only limited to IP addresses. Is there any such way to do the same thing, but to a certain URL, rather than IP?

Say, for example, that example1.com and example2.com share the same IP address, but you only want to spoof an IP packet for example1.com, not example2.com. Would this be at all feasible?

>>30
OP here, I never mentioned a game. I'm simply trying to send it to a specific domain that's using a shared IP address.

Say example1.com and example2.com have the IP of 127.0.0.1 (local IP, I know). If you send a spoofed packet, it gets sent to 127.0.0.1, but say I want to send it specifically to example1.com so that it would show up in the logs of example1.com and not example2.com. According to >>2 I would need to utilize the HTTP Host header. My question is where in the code of >>18 would the headers be placed?