I assume you mean Windows' version of named pipes / broadcast IPC?
If so, yes and no. No, mIRC doesn't support the actual mailslot protocol, so it won't listen for these messages. Yes, you can do IPC via DDE or SendMessage. No, you can't broadcast a single message to multiple endpoints. But Yes, you can write your own DLL to implement mailslot support. It would be as simple as registering as a mailslot endpoint and translating the messages to SendMessage.
