Overview
You want to reject the MT-FSM from specified alphanumeric originators.
Since the character * cannot be used in RTR’s alphanumeric lists, you chose to use the FAF Content Filtering instead. When matching using regular expressions, you noticed that the character ^ does not work as expected.
When you use the expression ^0001$, originator 000123456 is not matched but when you remove ^ and test again with 0001$, it is matched. However, you want to perform a full match instead of a partial match.
Solution
You can fix this issue by adding A after ^ as seen here: ^A0001[0-9]...