Regex: get only string in List where length is greater than N?

Hello all,
I have a List<string>, I would like to only get the string in that list where the length is greater, for example, 3 characters? I think using Regex will speed up the process, I don't want to do a loop and copy the List<string> to a new list.
So for example, this List<string>:
(0, "this")
(1, "is")
(2, "a")
(3, "test")
results in a new List<string> of
(0, "this")
(1, "test")
Any help is appreciated,
Thanks,
Kenny.

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