How to search the particular character in one word in asterisk server?

How to search the particular character in given sentence in asterisk server?

Ex:-

word="test"

here

word - variable name

test - value of the variable

I want to search the 'e开发者_StackOverflow中文版' character is present or not in given "test" value in asterisk server.

Is the any inbuilt command in asterisk server?

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The REGEX function returns 1 if data matches regular expression or 0 otherwise.

So,

exten => s,n,Set(foo=${REGEX("[e]" ${word})})

The foo returns the "1" because the letter "e" matched