PSVita DOSBox key remapping

Hello, I’m using the newest version of Retroarch on my PSVita with firmware 3.60 and it’s working realy great so far! However, now I wanted to try DOS Emulation. I downloaded the shareware version of Wolf3D for testing but I can’t play it because the controls simply won’t work. I’ve searched arround the internet for the last 2 days, and can’t find a way to map keyboard keys to the PSVita buttons. I also looked in the Retroarch Settings and in the files but no luck there. I appreciate any kind of advices.

(English is not my main language, sorry if there some grammar mistakes :frowning: )