Give u a RegEx, how to list all the Matches?

[cyhcyhhychyc]

To be simple,say give u a RegEx as below:
^[a-z]$

get: "a","b".... "z".

given ^/d{1,3}$
get:0,1...10,11 ...100,101....9 99

[tlhintoq]

You're going to have to try to word this better.

In English this makes no sense.