So, your goal is to search and replace?
According to the Official Visual Studio's keyboard shotcuts pdf, you can press Ctrl + H on Windows and Linux, or ??F on Mac to enable search and replace tool:
If you mean to disable the code, you just have to put <h1>
in search, and replace to ####
.
But if you want to use this regex instead, you may enable it in the icon: and use the regex: <h1>(.+?)<\/h1>
and replace to: #### $1
.
And as @tpartee suggested, here is some more information about Visual Studio's engine if you would like to learn more: