Really I don't understand your reply, sure for my ignorance: i go to study the -s operator

See perlrun for -s. It cause perl to parse command line arguments of the form: -XYZ=pqr which causes the variable $xyz to have the value "pqr" within the program or one-liner.

## run perl; enable arg parsing
perl -s 

## expand filename globs
-e"BEGIN{@ARGV=glob@ARGV}" 

## if between the tags, print filename(linenumber):line
-nle"/\[$TAG\]/../\[\/$TAG\]/&& print qq[$ARGV($.):$_]" 

## Supply the tagname to search for; and the fileglob
-TAG=tath_tag ./*/dir/*.ext
[download]

(Obviously, you'll need to put that all on one line to run it.)