I looked at coding up mouse commands myself but just out of curiosity and gave up without even trying. But I am sure it would be doable.
There have been several implementations copying the basic mouse commands from Genera in GNU Emacs:
https://www.mail-archive.com/gnu-emacs-sources@gnu.org/msg00393.html http://www.foldr.org/~michaelw/projects/redshank/redshank.el https://github.com/vsedach/mouse-copy
I stopped pursuing the idea after discovering that mouse use was giving me wrist pain.
Vladimir