How to commit a file with TortoiseHg?
To do this, you would need to do basically two things:


Create an Automator Service that commits the job
Add the Service to the context menu


Both of these topics has been answered here on Ask Different; I linked to two excellent examples.

What you would have to do is create an Applescript or a bash script (bash probably being easier) that "commits" whatever it is you want to commit - you will have to scope the requirements in detail.   Once you have the script written, add it to the context menu.