Basically, you need cocoa butter, milk powder, cream powder, and sugar. Tiny amount of vanilla--1/2%, and most companies use a tiny amount of soy lecethin-1/2%., thats half of one percent. The lecethin, in small amounts acts as a thinning agent--it mimics the addition of almost 10%cocoa butter. Obviously you can use cocoa butter instead.
Thing is, none of the ingredients will dissolve in cocoa butter, they are only water soluable. Chocolate mnfctrs use a milling process and then a "conching"process to mill the sugar and milk powders super fine. Pretty elaborate and expensive equipment, and I don't know of any small, countertop equivelent.
@lazar89, The OP wanted to know if they could make the white chocolate itself, not for recipes using white chocolate. Also, this forum is for pros only......if you're not a pro you should refrain from posting. Thank you!