Im wondering how i can use individual image buttons for each step?

There seems to be a StepNextButtonUrl property which will essentially use the same button image for all steps between start and complete which i guess is fine if you just want a button that says 'Next'

however id like an individual button for each step for example -

Step 1 - Set Preferences
Step 2 - Choose Design

Is this possible? i cant find any info on it... and i cant see in the properties how i isolate each step button although each step does have a unique id such as WizardStep1, 2, 3 etc so maybe there is a coding solution?