You can use the Kentico API.
Kentico CMS API Reference is avaliable at
Kentico DevNet.
As your question concerns adding complex functionality to Kentico and would require very in-depth explanations, I would recommend that you consider our paid consulting services which would offer you much more detailed and hands-on support for this project. You can find more information here:
Kentico - ConsultingYour question is particularly well suited for the consulting service. Keep in mind if you do have any specific questions regarding use of the API or you encounter any errors or general issues during your development, you can contact support as usual.
Best regards,
Martin Danko