Except of course with significant loss of detail (see Lesson 6 on POINT in my tutorial for how to resize images). Bitmap fonts are fixed images, unlike what are called "stroked" fonts. A stroked font is a set of formulas for creating the characters at any size.
If you check out my tutorial Lesson 11 on Fonts and Printing, you'll see how to create a font (which can be used with the PrintSTRING sub program) in any size and any style (that would include accented letters as you referred to above). It's a bit of work, mind you, but guaranteed to give you anything you want.