FireEvent in testComplete

Hi Everyone 

Is there a way I can use the FireEvent in my vb code in TestComplete?

I am currently using Keys to enter data in textboxes but I find it quite slow. The SetText or objTextbox.Text = Value works over twice as fast. The issue is these don't fire the onchange event in our webpage as the Keys method does. 

I thought I would be able to use something like

txtField.SetText("123")

txtField.FireEvent("onChange")

But it does not recognise the FireEvent method. 

Any ideas