When I want push keys into an application running in my terminal emulator, it's typically just a matter of writing the correct sequence to the pty file descriptor with a some mapping for special keys. For example, if I read KEY_F(1) then I turn around and write ESC[11~ (as prescribed by rxvt termdesc) to the pty and it gets picked up by the application on the other end. I assumed that supporting the mouse would be pretty much the same. If I read KEY_MOUSE then I write ESC[M and expect that the running app would pick up KEY_MOUSE.
I can see from my data traps that the application (using ncurses) sent a ESC[?1000h sequence meaning "SET_VT200_MOUSE". What I am questioning is what should I be writing back? ESC[CbCxCyM where Cx and Cy are X10 encoded coords? If so, does that mean that the coord values are limited to 223?