Web site to accept a POST, process and respond.

Question

Afternoon,
I need to create code and or module that will enable a Office Live Small Business Web site to accept a POST, process and respond.

I need to capture incoming POST, process the information and then respond with an HTTP response.

Is that possible if the web site is hosted by Office Live Small Business Web Site?
Can the code or module be secure?
If so is there an article or link with some details.

Just want to ensure that the POST will be accepted and my logic will be isolated from would be hackers.

Thanks,
Stephen