Hi, I'm trying to something along the following lines: > (define-struct posn (x y)) > (define my-posn (3 4)) > (define (foo posn-instance field) (posn-field posn-instance)) where calling (foo my-posn "x") would dynamically substitute posn-field with posn-x and the function would return 3. I don't know what to do with either "x" or posn-field to get this to work. I *think* I'm looking for something like a string->function function, where I could pass in "x" and posn-field would be replaced by (string->function (string-append "posn-" field)) I just don't know if there's something that currently serves that purpose or, if not, how to go about creating that function. Thanks, Todd