How to extract substring using regex given only the index?

Question

Is there any way to extract part of string/sentence, given only the from and to index of starting and ending position of the substring? Eg: "this is an example00001. and so on." and I need to get substring from position 10 to 15 (ie., examp) using regex.

Answer 1

Use a look behind anchored to start.

Using your example of position 10 to 15:

(?<=^.{10}).{5}

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If look behind is not supported, use group 1 of:

^.{10}(.{5})