mod_rewrite expertise needed

Hello,

I am trying to modify my WordPress .htaccess file and customize the mod_rewrite directives to allow for more complex URLs and passing variables to PHP while maintaining WordPress “pretty permalink” functionality.

Something like this:

https://mydomain.com/hello-world

(would work like WP does by default with pretty permalinks enabled)

https://mydomain.com/varA/hello-world

(would trick WP into displaying the same “hello-world” post as above, but also would pass the “varA” string to PHP as a variable)

https://mydomain.com/varA/varB/hello-world

(would again trick WP into displaying the same “hello-world” post as above, but also would pass the “varA” and “varB” strings to PHP as variables)

to further clarify, the mod_rewrite code would be outputting something like this:

index.php?varA=$1&varB=$2

in which case I could easily grab those variables in php using:
$a = $_GET[‘varA’];
$b = $_GET[‘varB’];

Lastly, the new mod_rewrite directives would still need to handle WordPress categories and tags which come in the form of:

https://mydomain.com/category/category1
https://mydomain,com/tag/sometag

BTW, the default WordPress mod_rewrite directives in my .htaccess file are:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

Thanks,
Devin