In Russ Cox's screencast of Acme, he was able to use regex "line numbers" like this:
/Users/rsc/demo/hello.go:/^func/,/^}/
right-clicking that opens hello.go and selects everything from func through the end of the function body.
This command doesn't seem to work out of the box. Where is this setting made?
You need to select the whole line while pressing the right mouse button. Right clicking will only try to go to the address, and doesn't do the matching. You can see in the video, that the line is highlighted with a dark green color.