Question : Need help using xcopy to backup file from previous 15 days

I am using xcopy to backup files when I get back in the office however I need to only backup files that have been modified in the last 15 days.  Is there a way to manipulate the xcopy so that it only copy's files from the last 15 days?

Answer : Need help using xcopy to backup file from previous 15 days

Robocopy is much more robust and will do what you need.  See http://en.wikipedia.org/wiki/Robocopy for info.  It was available as part of the Windows Resource Kit, and introduced as a standard feature of Windows Vista and Windows Server 2008.