Anyway - I already looked into that. It's what CGI::Application::Framework uses.
But it's not what I need/want.

That way I can only call some run_mode (method) from current module (one that is outputing
the template in the first place).  I would need to manualy add plugins to each of the module
(or just in base module). 


On the other hand, I could write an method in my base module (inherited by others). And implement
that logic inside of him (require SomeModule, call some_run_mode in it ...).
    

I don't know how much flexibility you need. I have a limited number of
run modes that my templates embed so I just place them in my base class.
I guess you could import them into your namespace or perhaps other list
members have more elegant solutions - I'm sure that there is one though
  
Indeed, there are a number of solutions that can be implemented.  HTML::Template::Expr with a function callback is probably the easiest solution.

Another possiblility is to use the modified H::T that I use (available at  http://members.optusnet.com.au/~mathew) to create your own TMPL_xxx syntax.

Mathew