REGEX to search for specific User ID

Hello.

What is the syntax to find, for example, a specific User ID using regex? All of the documentation provided gives examples of finding a range of User ID’s but not a specific one. When I tried to input, for exmaple, /^1645$/ which is one way of doing it, there are zero results returned but that User ID does exist. Also tried \b1645\b but that doesn’t work, either.

Thank you.

SOLVED:

To find, for example ONLY the subscirber id 1526 use:

^1526$

in the Subscriber ID REGEX expression tool.