How to add ReCaptcha on Registration

-- HikaShop version -- : 2.3.5
-- HikaMarket version -- : 1.5.1
-- Joomla version -- : 3.3.6
-- PHP version -- : 5.4.16
-- Browser(s) name and version -- : Chrome 40.0.2214.91
-- Error-message(debug-mod must be tuned on) -- : No

As I managed to do that on HikaShop registration form, I could not find a way to add ReCaptcha on Vendor registration combined with customer registration on HikaMarket.

Please Help!

Regards,
Iliya

Hi, Jerome.

Thank You for the fast responce!
I have Two...EDITED three more issues

1. ReCaptcha image position is OK on the HIKAMARKET registration form now, but it stays way too far on the left on the HS form.
2. Is there a way to keep most of the data in the form fields (like Name, Email...) after wrong code submission. I suppose ajax validation would be hard to achieve, but at least why don't you keep them in the session?
3. How to change the Captcha label according to the context language?

Regards!
Iliya