My application will be running on a laptop with a touch screen, which will be mounted in a police car and used by the officer while driving.  To make things easy on him/her, I'm making the controls large so they'll find the fingers of people with sausage fingers, like my own.

I'm using a MaskedDateTimeInput control on one screen for entering a TimeSpan.  This is going inside of a UserControl with two large RepeatButtons, one with an arrow pointing up and one with an arrow pointing down.  The idea is that the user will tap the screen in the MaskedDateTimeInput control, say in the seconds area.  The user can then tap or hold the RepeatButton with the Up arrow and I want the MaskedDateInput control to treat it as though the user had pressed the up arrow key on the keyboard.  The same goes for the RepeatButton with the down arrow acting like the user had pressed the down arrow key on the keyboard.

How can I get this functionality to work?  There must be some kind of a WPF command defined by the control but I don't know where to find it. 

Also, is it possible to specify how much one press of the up or down arrow key will change the value of the part of the time span it's in?

Tony