Greate stuff:
Online .NET regular expression tester with real-time highlighting and detailed results output.
Allowed me to quickly verify the pattern PWWWC\d\dFE\d\d_\d\d\d\d-\d\d-\d\d\.zip
matches only one of these filenames:
PWWWC07RI01_2016-01-10.zip
PWWWC08FE03_2016-01-04.zip
PAPPC00BT01_2016-01-04.zip
–jeroen
Source: .NET Regex Tester – Regex Storm