I must make use of a path found in a flexible to incorporate personal files within an shtml/SSI page. Essentially, I must set a flexible with mod_rewrite first after which process the filename included in the var.

<!--#include virtual="some_variable"-->

Is possible without needing another scripting language?

Make use of the E flag to create an atmosphere variable inside a rule, for instance:

RewriteRule ^ - [E=some_variable:foobar]

You'll be able to access that via:

<!--#include virtual="some_variable" -->

Used to do some additional tests, and so i think I'm able to answer my very own question:

Additionally towards the rewrite rule pointed out above, it's important to gain access to variables having a $-sign, e.g.

<!--#include virtual="$some_variable" -->