I don't know any way to cheat your stats, however if you google "rvdata2 editor" and press the first link, or just press it here, you can upload the file onto the site, edit the amount of credits you have and redownload it and replace your original file with it. However I found no luck in attempting to use it to edit the stats for my character, though I could've done something wrong.
Edit: Just like Indivi said, you can use Cheat Engine. I didn't think to add that one because I couldn't make it work. But I've found out how to now.
If you intend to use Cheat Engine for Lust Doll, or any RPGMaker game, any value you have needs to be multiplied by 2, and then you add 1, before you search for it. So if x is the amount of credits you have, then you would do x*2+1. (If you have 200 credits, search for the value 401, etc.) And then when you change the value you would have to change it to the value you want, multiplied by 2, and then add 1. So the exact same process as when you search.