You simply need to pass your content (be it Javascript or anything
else) through some approate variable @foo@ in the templated pages
until it ends up wherever you want it.
In they case of your Javascript, I'm not sure just where it should end
up. I see in www/blank-master.tcl
(on OpenACS 5.1.5.x)
some code doing stuff like this:
set onload {}
lappend onload "acs_initHtmlArea(editor_var_${htmlarea_id}, '${htmlarea_id}');"
which makes me suspect that those templates are
not set up to
let you pass in your own OnLoad stuff, you'd need to hack it to let
you do so.
Why don't you want to edit one of your master templates? It's not at
all obvious to me why you don't want to.