Traversing windows combobox quickly

Hi,
I have a combo-box control in my windows desktop application. It has around 500 items in it. Only 10 items is visible at a time. How do I traverse thru the list quickly to find an item and delete it. Sending up, down, pageup and pagedown keys is still very slow and makes the testcase execution time unacceptable. Any advise/guidance on how to approach this problem would be very helpful. Thanks for your time.