I want to try some algorithmic trading ideas.I have my own...

I want to try some algorithmic trading ideas.
I have my own software scanning and finding my entries but how do I go to next step of actually placing the order programatically.
I want to place orders on ASX via some sort of API.
What are my options for placing orders without having to 'point and click' on a web site.
I want to build a fully automated system.

Any ideas?

Thanks