Olindacat, an alternative depends on what software you're using to lay out your text.
In InDesign, for instance, you can create a character style that includes an underline for the letter you apply it to, and modify that underline in the style to set the thickness of the line to suit how it should look. And you can apply a vertical displacement to the underline, so that it actually appears *above* the letter. Since all these details are stored in the style, it's a pretty quick and easy solution.
WordPerfect can do much the same. Quark and Word may be able to do the same thing, though I'm not sufficiently familiar with them to advise on it. (And I doubt Word can -- it's just not that capable a program.)