Move files to different drive

Windows 2003 file server

Here is the script: (moves files that have not been accessed for 30 days to the drive E:\backup)

get-childitem P:\download -rec| where -FilterScript {$_.LastAccessTime -le [System.DateTime]::Now.AddDays(-30)} |move-item -destination "E:\backup"

issue: all files results end up in one single file backup even I specify E:\backup.

Questions: is there a way to move these files according to their source folder structures in the destination path E:\backup
ex:  source    Target
     P:\download\it\1.txt               E:\backup\it\1.tct
     P:\download\it\2\po.txt   E:\backup\it\2\po.txt
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Thank you.