What you're after is commonly called "fuzzy logic". Something like this can only be accomplished in a coded step. Our non-coded verification's can only handle static verification values since the values appear as strings as far as Test Studio is concerned.
In code you can parse the strings into int's or float's. Once you have a number stored in a variable in code you can do all sorts of range verification's on it. You'll still need to concretely define what is/isn't acceptable values so that you can write code that can correctly and automatically verify the values are acceptable or not.