I finally managed to set D-Pad to function as the C-Pad. And what the D-Pad did, now it will be done by pushing L+R+C-Pad, this just so the C-Pad still functions the same in case you wanna still use it.
Thank you so much to Kartik!, and also thanks to everyone else who tried to help me and took time to reply to me. I post this so I can help someone back who might be struggling with the configuration of this, maybe reading this could help that person.
This for the 'rehid.json' file:
{"keys":[{"press":"UP","get":"CUP"},{"press":"RIGHT","get":"CRIGHT"},{"press":"DOWN","get":"CDOWN"},{"press":"LEFT","get":"CLEFT"},{"press":"L+R+CRIGHT","get":"RIGHT"},{"press":"L+R+CUP","get":"UP"},{"press":"L+R+CLEFT","get":"LEFT"},{"press":"L+R+CDOWN","get":"DOWN"}],"dpadtocpad":true}
And here is the QR, for the settings I mentioned above: