Universal/prefix argument for "other window" redirection?

[Arthur Miller]

Is there already a way to "automatically" modify interactive commands to
"auto-work" in other window instead of current window?

I know I can scroll other window already and switch to some buffer in
another window with `switch-to-buffer-another-window`, I already use
them.

What I would like is to have all the cursor motion stuff, expression
evals etc, work on in other window so I don't need to switch back and
forth two buffers (I like to work with two buffers side-by-side). I
wonder if there is already something I could use; prefix
command/universal prefix whatever, to autmoatically modify behaviour of
interactive commands involved or do I have to write my own (if it's
possible :))?