Custom Controls with multiple content in Expression Blend

Xerxes80

Hello,

i want to create a custom control with multiple contents where each content
is editable as a separate child inside the interaction panel of Expression
Blend. For example like the System.Windows.Controls.Primitives.Track control
(DecreaseRepeatButton, IncreaseRepeatButton, Thumb).

How can i create such a control??

Thanx in advance,
Xerxes