F-Sy-H: How can I add another git subcommand with highlighting identical to git commit?

[tjk213]

Hello internet! I have a git alias called commit-checked which is defined with a shell command:

[alias]
        commit-checked = !python $HOME/my-wrapper.py

Could anyone here tell me how I can add this as a new git subcommand in -git.ch so the --message arg gets highlighted the same way it does for git commit? I am okay with something hacky.

Thanks!