How to define the size of a multiline input?

How to define the size of a multiline input?

 I want to make the box (on the screen) larger for a multiline field. I see how I can do it with zc_TextAreaWidth & zc_TextAreaHeight if I were embedding the form in a web ap - but I'm not - I just want to change the look of my multiline box on my regular "form". Can it be done? Thanks