Custom Page Parameters

I have a page called ‘artworks’

https://domain.com/artworks/

Now I want to pass it a parameter, with nice permalinks and it will change accordingly. So what I have done now is alter the .htaccess by putting in an extra IfModule above the wordpress rules.

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /test/wordpress/
# RewriteRule artworks/([^/.]+)$ artworks/$1/ [R]
# RewriteRule artworks/([^/.]+)/?$ artworks/?a=$1 [L]
</IfModule>

However, that doesn’t work, as the result is

https://domain.com/artworks/somestring/

Which is what I want, but wordpress interprets that as a subpage and gives me a 404. Which surprises me because I thought it would interpret ?a=somestring.

Also, if the result is

https://domain.com/artworks/somenumber/

I can actually get the data via $_GET[‘a’], which gives me a number. But again, I don’t really want to have some random number in the URL.

Does anyone have a workaround for this? Would be most helpful, thanks. I don’t really want to do this

https://domain.com/artworks/?a=somestring

As it doesn’t fit in with the rest of the permalinks in the site.

Thanks again
Daz