Redirect spawned process to tempfile with the pid in its filename

Suppose myprogram is spawned through the terminal (bash) and gets pid of 1234 (different everytime). I want to redirect, both stdout and stderr, to a tempfile named abc-$PID (if the PID is 1234, use tempfile abc-1234. The code looks like this now:

myprogram > /tmp/abc-$! 2>&1

it doesn't work Please help.