My dd (now 20 months) is lactose intolerant, and like your dd is on hypoallergenic formula. Our HV referred us to a dietician, effectively by-passing our GP .
The advice I was given was to avoid all dairy at first because even a little bit of dairy gave her tumy ache, but try her with soya alternatives, eg yoghurts, etc (Alpro do a really good range), and also to try introducing soya formula (not soya milk from cartons because it doesn't have the right vitamins/minerals) rather than milk formula - we use SMA Wysoy.
So for weaning I started with baby rice made with hypoallergenic formula, mashed banana, fruit pureee, then veg like potatoes, broccoli, carrots and cauliflower cooked until it was quite soft, and baby rice cakes. Then I introduced whatever I was making for us thoroughly mushed (at first I sieved it as well).
I've got very good at reading labels - it doesn't take long to work out what brands of bread, baby snacks (Organix ones are good) are suitable. I've modified my cooking to suit dd in that I don't make creamy sauces any more or use cheese in cooking (if dh and I want it, we add it later), but I mostly cook from scratch anyway. If you use ready prepared things, then your choice will be restricted as you will find milk and lactose in a lot of apparently random products.
For baking or anything in cooking that needs butter I use Pure sunflower spread - it works a treat, and it is OK to use soya milk in cooking as long as you don't use it in dd's bottles. You can make custard with Wysoy, but the taste and consistency is weird - I use Alpro ready made soya custard, which tastes like the real thing! I found Annabel Karmel's baby and toddler cookbook useful for ideas. Where she uses butter, substitute sunflower or olive oil, or Pure spread.
Dd can now tolerate little bits of dairy, which makes life a lot easier, as I don't have to worry about making sure I have food for her - it's amazing how many places have very little on the menu that doesn't involve some form of butter, cheese etc .
HTH