Create a WebI variable on the base of string that has dynamic values

I need to crate a variable on the base of a string which has dynamic values.

This string has various values that I want to indicate with some identifier.

Suppose I have value "afdfa2324 MMA 7897acncn" that I want to identify as "MMA" and I have a value "A2M3" that I want to show as "Mark". The pattern remains (AlphaNumericAlphaNumeric) the same but value changes. I can get the value for the first one using If statement but since the Values are changing for the second one I don't know what formula to use.

appreciate your help. Thanks