Zoom Property [Excel 2003 VBA Language Reference]
Returns or sets a percentage (between 10 and 400 percent) by which Microsoft Excel will scale the worksheet for printing. Applies only to worksheets. Read/write Variant.
expression Required. An expression that returns a PageSetup object.
If this property is False, the FitToPagesWide and FitToPagesTall properties control how the worksheet is scaled.
All scaling retains the aspect ratio of the original document.
Returns or sets the display size of the window, as a percentage (100 equals normal size, 200 equals double size, and so on). Read/write Variant.
expression Required. An expression that returns a Window object.
You can also set this property to True to make the window size fit the current selection.
This function affects only the sheet that's currently active in the window. To use this property on other sheets, you must first activate them.
This example scales Sheet1 by 150 percent when the worksheet is printed.
Worksheets("Sheet1").PageSetup.Zoom = 150