>I need to simulate a keyboard on screen for entering alfanumeric data.

I don't know of one that exists in public domain, but I made one out of a toolbar class, that simply did a "KEYBOARD 'a'" in all the buttons (with different letters of course).

Another option is getting an existing progam, I know there is an On-Screen keyboard by Madenta that is included with Windows 2000, otherwise, check out: http://www.microsoft.com/enable/products/aids.asp and look for all the On-SCreen keyboards.