U8glib - add one more character when using reduced fonts

Hi folks, I use two fonts in my project, both are reduced (u8g_font_helvR08r, u8g_font_helvR14r) to save some program storage space. But, I need one more char '°' to be printed on my display.

Please, is some way, how to add 1 or more special characters to existing font? Or I have to draw this as my own bitmap?

edit: I am just thinking about making my custom fonts array data with added character?!

Show us the code you have, including the file that defines the fonts, and the source file that uses the font data.

What happens when you try to print a degree symbol?