Access reports are always read-only in that you can't make any changes to
what's shown on them.
Are you saying that you're outputting the reports to a file and want the
file to be read-only? In that case, saving them as Snapshots, or printing to
PDF files would be two options.
As for Excel, you'd be better off asking in an Excel-related newsgroup.
There are several starting microsoft.public.excel.