As Simple as sound... It'll be great if you can create parameters in a family ruled by string. String ruled filters and/or real queries will be a big improvement too.
Yes, the "string rulled" formulas is the same as the idea in the link.
But with string manipulation I mean, text functions like in SQL queries or excel formulas like Concatenate, Left, Right, Substitute, Trim, Value, UpperCase, LowerCase, Title, convert Text parameter to Number/Length, etc..