First, you should have taken a good look at the error messages. You could use the internet function provided by IBM, Lookat.http://www-1.ibm.com/servers/eserver/zs ... ookat.html
If you would have examined the error messages you would have found out that the data set is not cataloged, and it tells you which one.
A123.VDSN. This is supposed to be a model for your define. You probably missed that you do not have a model A123.VDSN, but you might have a VDSN model. I assume that the problem is that your userid is prefixed to your VDSN. Besides that, I take it that VDSN has not been supplied with a real name for the model. This should get you started in the right direction.