Event when a Button of an Extension is pressed

Zoggo

I'd like to register a click or execute Event when a Button (stamp current position to log) in the GPS Extension was pressed. I already can gain access to the ICommandItem:

            Dim pCmdItem As ICommandItem
            Dim pUID As New UIDClass()
            pUID.Value = "{256176AD-0C33-406C-9ED8-9F7AC784A3E3}"
            pCmdItem = My.ArcMap.Application.Document.CommandBars.Find(pUID)

But how can use events like click, execute oder disable of this Button?