In a given string, find the substring between Start_string and End_string.

You will have to include or exclude the Start_string and End_string as a part of the substring depending on the third argument 'include_se'

If include_se=1, include the Start_string and End_string as a part of the extracted substring, else exclude them

Example:

input_str: 'This is a test sentence'
Start_string: 'is'
End_string: 'sentence'
include_se=1
extract_function(input_str,Start_string,End_string, include_se)= 'is a test sentence'