Which legal documents are required to establish XX% profit of a
private company to go to an individual?

I am one of the partners of a three people start up, one provides
financial backing, the other legal and idea owner, and I do all the
technical work.

I want to protect myself from the owner not paying me or hiding
profits. I am entitled to a certain percentage of the profit and want
a document that would hold up in court.

In your answer I want:
1) Specific document/wording/reference for the legal document
establishing by monthly payment of a certain percentage of the
company's profit

2) Specific docuemnts that give legal rights to the owner to sign
above mentioned document -- ie -- if one signs it and is the person
who registered the business and bank account, is that enough?