Automatically find position, from what last command started in tmux

It is common practice in tmux to start some command, then switch to copy mode, scroll to the position, where is this command started and look over the command output. It is difficult to find the position, where the command was started, especially if the command output is pretty long (longer then the visible screen itself). So, it would be useful to write a script to perform this search and assign a keyboard shortcut to. How to write such a script?