Try the CAB if you're getting nowhere with the sol.
You'll get 15% of his net salary if you apply to the CSA, less 1/7th for each overnight he has her. If you can come to an agreement between you (get it in writing) then do so, otherwise apply right away as your backpayments start from the date you apply. In addition you can apply for extras in financial situations where a child/family would have expected school fees etc to be paid, so you can ask the CSA to take that into account and make an assessment for those.
Also you have scope to apply under the childrens act for a financial settlement on behalf of your daughter, where if he has the means then you can go to court to get money towards things like a house if he can afford to provide one.
If you were married then there will obviously be the financial separation to sort out too. If you're working, even only getting a small salary then you may find you don't qualify for legal aid. But you will get the full amount of maintenace due from CSA calculation.
Presumably he completes a Tax Return, so they shouldn't have too much trouble calculating the figures and aleady have his SATR somehwre in the Revenue system.
Seeing her dad is important, perhaps now he has realised where his priorities should lie and he will start to build a meaningful relationship with her. Do everything you can to encourage it for your daughter's sake.
Gilly