"Resetting" a rotated image

Hi all,
I’m just acquainting myself with webanimator; after rotating an image a specific amount (using RotateZ), I’d like to reset it to its default orientation easily. Is that possible? I’m trying to create a simple input control that allows the user to select a compass point (in 30-degree increments). A graphical arrow in the center shows their selection. I’d like to reset the arrow position when necessary. Thanks!