hi Paul,
there isn't a way to configure / format the prompt pages & controls that the end user sees. what you may wish to do is to create a String / Text type parameter and use the Edit Mask to configure what they are allowed to enter. you could define a single parameter wherein the end user has to enter
yyyy/MM where the entries are defined as numbers.
see your online help in crystal and then enter Edit Mask in the Search tab. for example the edit mask could be 0000/00. see more in the online help by looking at
Defining entry type and format using the EditMask