Yes, be sure to read the text at the beginning of the ini files and the documentation in the c:\program files\riderunner\Documentation folder.
For me, I wanted a button to jump to next/previous artist so this is what I did:
I assigned keys to press using the joycon software.
Using keycode.exe I found that my button gave me 6078 and 6080.
I put those numbers into keytbl.ini like this:
Now, those NEXT and PREV are predefined skin commands, I wanted them to do something else when in the audio_browser.skin
So, I put this in the exectbl.ini
Now when I'm looking at the audio_browser.skin the NEXT executes "DOWN||CLEARLIST||ADD1||UP||PLAY"
A single command can be used or like in my case multiple commands are separated by ||
RR executes the commands in order from left to right.
Read the 'skin commands.txt' for what commands are available.
Hope that helps.