How can I have a dough attachment when I have a Dretec Handmixer?
AFAIK it's really difficult to knead dough with a hand mixer even if it comes equipped with dough hooks.

I was in your shoes a while ago too and after some research, found that it's basically useless for kneading dough. Unless you're Popeye, you're not going to be able to hold the mixer and the bowl steady enough for the dough to get kneaded. I ended up buying a KitchenAid.

Either spend the money on a stand mixer or just knead your doughs by hand.