Ajax Control Toolkit ModalPopup - Dismiss with OK and invoke server method as if Button OnCommand with CommandArgument

I have a scenario where I want to use the ModalPopup when a form Button is clicked to ask the user to confirm an action. If the user clicks the ModalPopup OK button I want to invoke a code-behind method that uses the same CommandName and CommandArgument that would be used from the Button without the ModalPopup. Any idea how this can be acheived?