301 Redirect capture group for everything after folder name /folder/*


we used to have our blog under mydomain.com/blog , not it has moved to blog.mydomain.com

i’ve setup redirects of this type

/blog -> blog.mydomain.com
/blog/(.*) -> blog.mydomain.com/%1

the idea is that if someone ends up in an old website link e.g. www.mydomain.com/blog/post/1 it would be redirect to blog.mydomain.com/post/1 the point is that does not work. My guess is that the (.*) matches till the / so if there’s no slash e.g. www.mydomain/blog/123or many www.mydomain/blog/post/123 the rule is not met.
especially my former blog does not have a ending \ so all the urls are of the form www.mydomain/blog/123

how can I fix it.? is there a way to say "all that is after /blog/* redirect it to https://blog.mydomain.com/%1