Alternative to wake on LAN
If I'm understanding you correctly, your router currently blocks the magic packet?

An embedded webserver (port forwarded) behind your router sounds like one way to go. This can also be the device that generates the magic packet on the local LAN to wake your PC without having to hack a relay/switch so it can be done all over existing ethernet - assuming that your router won't block any locally generated and sent magic packets &lt;- you can test this first by using another PC to try to wake the target PC all on the local LAN.

If that works, you can make it really easy with an embedded Linux SBC (single-board-computer) combined with your choice of a light-weight open source webserver.