Magento

I’ve got custom fields (dropdowns) for height and width.  In order to calculate an area, I need these to be saved with a value in inches, but I’d like to display to the user something like 1’ 2”, instead of 14.  (as an example.)

Is there a way to set custom options to have a value and also a display field that are different?  Is there an extension that already does this? 

Thank you,
Robert