WordPress and htaccess domain redirection, URL showed in address bar

Dear all,

I have a domain, let’s call it https://www.mydomain.com
And I have a blog, let’s call it https://www.myblog.com/myfolder/myslug

As I need people to go to https://www.myblog.com/myfolder/myslug everytime they type https://www.mydomain.com, I have edited htaccess and added to the IfModule:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^.*mydomain\.com$ [NC]
RewriteRule ^(.*)$ https://www.myblog.com/myfolder/myslug? [R=301,L]

And this words great. But in the address bar shows https://www.myblog.com/myfolder/myslug and I would like it to show https://www.mydomain.com .. How can I do this???

Thanks a lot in advance!