create an in - fill plate within a tube

Hi

Attached is PDF file showing a 600dia tube with an infill plate 800mm down.

How would i go about creating this 20 thk infill plate. Because it is set in at an angle the shape will be elliptical.

I would like to have both tube and plate as one then split into separate parts.

Could someone explain / post an example of the process.

thanks

Mark (Solidworks 2009 SP 4)

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