Regular expression question

[Omair-Inam Abdul-Matin <oi...@cs.uwaterloo.ca>]

I would like to catch the following pattern:

A substring in the file beginning with the pattern "Importing file" and 
ending with the pattern "Modified.*rows in.*table", possibly spanning 
multiple lines provided that it contains the string Exception.  The 
substring should not contain the beginning or ending patterns more than 
once...

The following command almost works, except that it may return strings 
that contain "Importing file" multiple times:

perl -0777ne "print m!Importing 
file[\s\S]*?Exception[\s\S]*?Modified.*table!g;" test.txt

Does anyone know what changes I could make to the regular expression so 
that it prints out the correct pattern?

I've attached a small test document for anyone wanting to test out ideas.

Thanks,

Omair