How to do the. htaccess file 301

How to do the. htaccess file 301
I want to make this address www.bbbb4.com/www.xxx.com.html 301 to
Www.bbbb4.com/www_xxx_com.html

Where www.xxx.com is a domain name (not fixed), there may be n points as
Www.xxx.xxx.com
Www.aaaa.net
www.bbbb.org, wait.


I mean "." in the domain name. Replace with "_"

Www.bbbb4.com/www.xxx.xxx.com.html is 301 to
Www.bbbb4.com/www_xxx_xxx_com.html

Please write out the code to thank you.

------Solution--------------------
Same request!
------Solution--------------------
Rewriteengine on
Rewritecond%{http_host}!^www.bbbb4.com/www.xxx.xxx.com.html$ [NC]
Rewriterule ^ (. *) $ www.bbbb4.com/www_xxx_xxx_com.html/$1 [l,r=301]

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