SSRS 2008 report header holding the company logo and report title when exporting to excel or csv formats

I need to surpress the report header holding the company logo and report title when exporting to excel or csv formats, how can I do this in SSRS 2008?

Hiding items using a parameter...
Create a Boolean type parameter.  I'll call it HideHeader
Place all of the header items in a rectangle in the top area of the report body.
In the Hidden property for the rectangle, use the expression:
=(Parameters!HideHeader.Value)

Hiding the header only for Excel rendering...
Again, this is new feature in SSRS 2008 R2.
Use the new RenderFormat object in an expression on the Hidden property, like this:
=IIF(Globals!RenderFormat.Name="EXCEL", True, False)

...actually the IIF function is unnecessary.  You could use the same logic as my first example:
=(Globals!RenderFormat.Name="EXCEL")