[Hampshire] OpenVPN GUI

Hello all,
I'm planning to roll out OpenVPN for the company I'm currently on placement
with for their new intranet, when I've left they need to be able to easily
update certificates to the server as they add more stores to their chain.

>From both the perspective of adding certificates at Head Office and
employee's adding certificates at each individual store.

Can anyone recommend any GUI that works on windows?

Regards