How to construct a one off real estate deal

[Cesar Espino]

Hello BP, I have a unique situation and not sure how to construct an agreement and would like some advise. I do investing in Los Angeles, my brother has a house in Long Beach that was a really bad purchase from the beginning, long story short he asked me if I can help him fix it and ultimate flip it. I have agreed in helping him and I've already brought my contractor, we have a layout and are going to start the remodel. My question is, I (my company) will be funding the fixing and will ultimate bring one of my realtors to sell the property. How do I go about ensuring that at the time of closing, the total cost of fixing plus my fee for the fixing and coordination gets into escrow and I get pay out at the time of close and my brother only gets the remainder from this sale? How can I construct this agreement?