Com crédito para @DavidPostill:
# FD_VBA_Backup.ps1
$date = get-date -format "MMddyyyy HHmm"
$fnft = "VbaProject - " + $date + ".OTM"
$source = "C:\Users\OCCReportManager\AppData\Roaming\Microsoft\Outlook\VbaProject.OTM"
$dest = "D:\FD Automation VBA Backups\" + $fnft
copy-item $source $dest # results in eg. "VbaProject - 07202015 0936.OTM"
(Get-ChildItem $dest).LastWriteTime = Get-Date