buttons acting as arrow keys in wpf

Question

Im using a <span style="background-color: yellow;">treeview</span>, when i hit left arrow in keyboard the selected item in treeview expands and when i hit down arrow key the next item in the treeview is selected..So here I have two Buttons <span style="background-color: yellow;"><span style="background-color: yellow;"><span style="background-color: #ffffff;">btnStepIn</span></span></span>, btnStepOut which should exactly act like left and down arrow key..On <span style="background-color: #ffffff;"><span style="background-color: #ffff00;">btnStepIn </span></span>button click <span style="background-color: #ffffff;"><span style="background-color: #ffff00;">right arrow</span></span> key functionality should be performed and on <span style="background-color: #ffff00;">btnStepOut </span>button click <span style="background-color: #ffff00;">down arrow</span> key functionality should be performed..&nbsp;