Lines above fingerings for string indication

As a violin player and composer, one of my favorite ways editors indicate which string a violinist (or any stringed instrument) should play a particular fingering on is by using a single, double, triple, or quadruple line over or under the number indicating the fingering. The lines are on the outside of the fingering (so fingerings on the bottom would have lines below and fingerings on the top would have lines above) to distinguish them from tenuto markings. I realize I'm probably not describing this well, so I've attached some examples I've found. It would be fantastic if this could be added. I realize I can just put a second numeral to represent the string, and I've often seen Roman numerals used, but I find this bulky and it's often misinterpreted as a position indicator. There is currently a feature which allows the user to box in or circle the fingering, so I would assume that is where this feature would go if implemented. Let me know what you think (and let me know if there is already a way to do this without physically drawing tiny lines over every fingering which needs them)!