Hi,
It's not my area of expertise, but it should be possible to use the same certificates for all sub-domains of the same domain.
This is not what I do in my procedure
How to activate SSL with Wampserver and it's not what will be done in three clicks with Wampserver 3.3.2.
That's the kind of question you should be asking at ApacheLounge.
---------------------------------------------------------------
Documentation Apache -
Documentation PHP -
Documentation MySQL -
Wampserver install files & addons