Ramiro when I got fonts from fontlab and I converted them to UFO I had to transfer kerning between some files. So I have written a Robofont extension that transfers kerning between opened fonts on glyph by glyph basis. It doesn't have the option to select right kerning / left kerning but I may add it in future if I need it. I haven't shared it because I want to start a website and I want to add it to the download section. this is my email firstname.lastname@example.org. If you think that would help just send me an email with the same subject.