A couple of ways you could do this. The first being double clicking the dimension, the checking the "hide dimension value" checkbox, then typing what letter character you wish displayed. As to another way to do this, more dynamically, I'll have to get back to you when I have time, or someone with more familiarity with it may walk you thru it before I get to it.
I second chad38's solution, hiding the dimension value and manually typing in the parameter name.
I would add that by creating an iPart as the "standard" and insert the factory part into a drawing, then you can use a general table and the view of the factory part to quickly document the changing values of the parameters in a somewhat automated fashion. See the attached example and let me know if you have any questions.
Thanks,