You can use double quotes inside the one-liner:

perl -nle '/tilda/ && s/\[// && s/\]// && print qq{insert into mytable values(SEQ_MY_ID.nextval, "$_", "01",sysdate,"","")}' report.conf

That works as long as $_ doesn't contain double quotes, and your database engine has not problems with double quotes..

If you use double quotes on the outside, the shell tries to interpolate $_, so you have to escape it with a backslash: \$_