Match pattern

Hello.

I am trying to extract data from multiple text documents that go like this "abcdtwy teujh M: +1.2345678e000 mkgtd", and the number +1.2345678e000 is what I want to extract from the string. I can use string subset to separate the number from a single document, but the offset and string length of such data vary in different documents. Therefore, I am thinking of using match pattern to extract the entire string between "M:" and space.

I wonder if the match pattern function works in this situation. If so, what regular expression can I write to specify the string between "M:" and space?

Thanks a million :smileyhappy:.