Yes, its a long story... I am actually using TemplateToolkit in another part of this application. However, the part I'm trying to figure out here has to be end-user-editable (also from a web page that lets them edit the aforementioned textfile.)
The point above about the system() call is a good one. Methinks there are probably too many security issues with letting people define perl code to be executed by the system... the sandbox isn't well enough controlled.
Alrighty then... back to the drawing board.