Change fallback font for unusual letters

Hi folks,

I did a little game in english with the bitwise font. Now I tried to add different languages and bitwise doesn't has some of the letters like ä or ñ...

I noticed that Construct 2 is kind of smart and just displays these letters in a different "fallback font". Sadly that font is totally different to bitwise. I would like to change that fallback font to something that at least comes close to bitwise. How can I do that?

Thanks a lot!