I'm in NC now but I was born & raised in PA. And I confess I'm having trouble figuring out how "I don't care to do that" means "yes, I'd be delighted"
" I don't care
if I do that" makes a bit more sense to me -- kind of like "don't mind if I do" which generally conveys much more enthusiasm than the bare words would suggest to me.
I guess maybe it's like "I could care less" which actually means I could *not* possibly care less than I do right now. Or "That ain't nothin'" which, again, means that it *is* nothing.
English is a funky language.
Which is what makes writing in it so fun.
PJ