Hi
File / Page Setup / Margins......set left and tight margins to equal amounts.
You might also try ticking the centering check boxes.

HTH
Michael

"mirroring" wrote:

I have 300 pages in an excel document which need to be double sided and bound
into a a publication. I need to mirror the pages so they have the same
margin on both left and right depending where they fall in the document. Can
anyone help please?