So, it's trivial allright, but maybe someone didn't think of it so
far/is a UNIX newbie/is a Mozilla newbie:
How to use Unix-Mozilla efficiently as "web browser path" in 3.0.5,
using the features outlined in
case "$MODE" in
"$MOZILLA_PATH"/mozilla -remote "$OPENURL_CMD"
So, just enter "/location/of/scriptfile (new-tab|new-window)" in the
"web browser path" field in config and you're set.
God bless modern browsers! ;)
This will work with any Application that passes the URL at the end of
the command line.
So, basically, this is a feature request, too, since with a
URL-Placeholder for that field even that trivial script would be