for example, you can use SendMessage.
http://msdn.microsoft.com/library/default.asp?url.../keyboardinput.asp
See especially the Windows messages: WM_KEYUP, WM_KEYDOWN, etc. to send single keys...
Nevertheless, such methods should (and can) be avoided by sending the appropiate message/API instead. Use sendkey-stuff as less as possible. In fact there are always better ways to do it (depending on what you exactly want to do in the end).
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