I think I would have done something like this:
$path = read-host "Enter/paste path"
$localdesktop = $env:userprofile, "\desktop" -join ("")
$xlsdoc = Get-ChildItem -path $path | where {$_.Name -match ".xlsx$" -and $_.Name -match "ZZZ"}
Copy-Item -path ($xlsdoc.FullName) -destination $localdesktop
$copiedxls = Get-ChildItem -path $localdesktop | where {$_.Name -match ".xlsx$" -and $_.Length -match $xlsdoc.Length}
Sleep -s 5
start $copiedxls.FullName
start $copiedxls
Edit: I use the '.lenght' property to compare filesize. This is how I determine wich "zzz.xlsx" to start.
Erlend.