Problems with .htaccess: incorrect directory handling?

Question

Apache HTTP Server

Tell me, what is the problem that my rules do not work?
It is necessary that the subdomain works with the subdirectory of the site as with the root one: going to the address sms-rassilka-barnaul.sitename.ru should open the directory /cities/barnaul/*
And so for many cities.
Previously, it was prescribed forcibly:

RewriteCond %{HTTP_HOST} ^(www\.)?sms-rassilka-barnaul\.sitename\.ru$ [NC]
RewriteCond %{REQUEST_URI} !^/cities/barnaul/ [NC]
RewriteRule ^(.*)$ /cities/barnaul/$1 [L,QSA]

write according to the pattern

RewriteCond %{HTTP_HOST} sms-rassilka-([a-z]+)\.sitename\.ru$ [NC]
RewriteCond %{REQUEST_URI} !^/cities/%1/ [NC]
RewriteRule ^(.*)$ /cities/%1/$1 [L,QSA]

and throws out a 500 Internal Server Error. And for some reason, it is the second line that is not processed, everything is transferred to the third.
PS Site on Bitrix, MB is it somehow corrected?

Answer 1

Decided! The correct code is this:

RewriteCond %{HTTP_HOST} ^sms-rassilka-([a-z]+)\.sitename\.ru [NC]
RewriteRule ^((?!cities/.*).*)$ /cities/%1/$1 [L]