In your code you don't "copy an Excel Sheet" to one variable!
These command's mean:
Dim Store1Sheet() As Variant
Store1Sheet = Range("A1:D99")
I'm not sure what you want to do...
Please, be more specific, improve your question and i'll try to upgrade my answer.
More about MS Excel objects: http://msdn.microsoft.com/en-us/library/office/aa209782%28v=office.10%29.aspx
More about MS Visual Basic Reference: http://msdn.microsoft.com/en-us/library/office/aa269683%28v=office.10%29