Custom Error Pages with proper HTML code

#1
Scenario: Need to set custom error page for a domain/virtual host, let's assume for FORBIDDEN content, with return HTML code 403 - which is vital being received & logged, as it plays into blocking such consecutive requests via modSecurity module.

The rewrite code in question which blocks requests for exe & asp extension files :

RewriteRule \.(asp|exe)$ - [F,L]

I am aware that one can specify custom error pages in the OLS webadmin for each virtual host in the General tab, problem is; once specified a custom 403 page here it starts working as a REDIRECT (HTML code 301) instead of 403, and thus modSecurity can not catch it.
Makes no difference if the custom page is entered as an URL ( https://mydomain.com/403.html ) or as local file relative to the Doc Root ( /403.html ), they both function as redirects instead of includes/links.

The only solution I found is to delete/not specify a custom 403 error page, and thus 403 code is correctly returned & logged, but then the default OLS error page remains to be displayed. :(

What we need, respectfully request, is a way to have custom error pages work the same way default OLS error pages function, have them linked/included from within the DocRoot (better yet, the $VH_ROOT) returning the proper HTML code instead of just a 301 redirect.

BTW, until this is implemented, where exactly is the default 403 error page located in the OLS install directory? I fould the 404 page in the Examples dir, but not the other error page templates.
 
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