Post order on a third party system - Make payment through WHMCS

[codemaster2008]

I know in a way it defeats the purpose of WHMCS but it is a anusual scenario:

 

I'd like to use my own order form which already exist, is part of my custom application, I have total and absolute control over it and it is not related to WHMCS at all.

 

The idea is that people would signup from my form and when they click the "Subscribe button", I would be posting the order to WHMCS through some API and once the order is posted, I would redirect them to the WHMCS payment page.

 

So, the transiction from my application order form and WHMCS payment page would be transparent for the end user.

 

Is it possible? And if the answer is yes, how?

 

I appreciate any help;

Thanks in advance.