I tried to configure my DNS today, and I realized that it was much more complicated than I thought, because it is necessary to consider the consequences for google referrals which penalizes the "duplicate content".
I tried several solutions:
-redirection (visible or invisible) proposed in the OVH interface: it is simple to implement, but may handicap referrals
redirection by. htaccess files seems powerful, but complex to implement, and requires host a site for each domain.
-html-forwarding: problems for referrals.
-create Cname and A records in the DNS: I have changed, and I made my site inaccessible.
-blogspot interface to use a personnal domain worked a few minutes, and then made my blog inaccessible
I really have to study DNS, but the blog may become inaccessible for some time.