Redirectmatch from https to http - urgent

Hi,

I have a couple of folders being accessed via https as set by their htaccess files, which both contain the following:

RedirectMatch (.*)$ https://www.somewhere.com$1

I would like to put a rule in the root folder of the website which ensures all other folders are not accessed via https - to effectively rewrite https to http for all folders apart from ones that contain the above.

OR there might be a couple of rules I can slot into a single htaccess file at the root? I've RTFM and am still scratching my head, I've got people breathing down my neck, please help!

thanks
John