You mean you have already written the code? If so, you might want to consider finding some examples from your broker and inserting it -- most brokers have pretty good example code, and often don't send it to you unless you ask.
One caveat: if you haven't actually written the code in a computer-like language, or if it's defined very loosely (e..g, buy low and sell high ), you may find that it's a lot more actual programming code than you foresaw.
You might want to specify what language your broker's API uses, as many programmers only know one language/operating system or another (e.g., Java on Linux vs. Microsoft Visual C++). Programmers are easily retrained, but it will take them a lot more time (and cost you a lot more money) if they're using a platform they've never touched before.
What kind of API are you looking at and which brokerage do you want to integrated with?
I specialize in custom financial and trading software development have been working as a software engineer for over 10 years and currently looking for freelance work.
We will implement your API. Which are you looking to use? F.I.X gateway? C#, Java?, C++, they are all pretty simple. If you can give a bit more information, usually it takes maybe 4 to 5 days complete.