Enhanced Excel Encryption/DRM Software?

Any one know of some good Excel Encryption/DRM like software?

I am having trouble finding anything reputable. We have some Excel files that are to be sent to users, we don’t want the users to be able to edit them at all and if possible restrict printing and even a timeout/expire for the document.

So far only thing I have found is:

http://en.china-drm.com/excelencrypt.asp

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