To do this correctly, the host doing the queries needs to have multiple IP addresses. I don't know how this is done in Windows, but under Unix it can be accomplished using IP aliasing or whatever synonym is appropriate for your OS variant. Contact your system or network administrator for help with this.

Once the machine is configured with multiple IP addresses per your needs, make use of the bind function before you make your outbound connect (this can be done with IO::Socket just as easily using the LocalAddr variable). This ensures the outbound connection comes from the IP address (and port, if you want that level of control) that you want.