He ... I still do not know what the origin tag field is, so I assume it is the TITLE tag field.
I hope you are able to adapt it to your needs?
As usual - there are many ways to do so in Mp3tag.
To go the easy standard way you would use the ready made converters and user definable action groups, normally it would cost two or three basic action steps to solve this task, not so heavy for the user, this is what Mp3tag makes so powerful. You should learn to use the action toolbox to solve your problems at your fingertips.
As usual - there is also a tricky way.
For example, use an action "Guess values".
And this works too ... with action "Guess values".