Thank you for contacting us.
I would like to draw your attention to the project from the following code library thread:
It illustrates how to use skinnable form controls (checkboxes, radio buttons or buttons) and apply styles to them using skins. Furthermore, you are free to utilize the ValidationGroup property (supported under ASP.NET 2.0 or later) for buttons of your choice.
I hope these directions are helpful. Let me know if I can be of a further assistance.
All the best,
the Telerik team