Tak som to nakoniec poriesil, nie je to uplne idealne, islo byt to vysperkovat, ale pre potreby staci:

$date=(get-date).AddDays(-3).ToString("yyMMdd")
$filepath="C:\Users\<user>\Pokus3"
$file1=gci "${filepath}\New1TextDocument${date}*" -name
$file2=gci "${filepath}\New2TextDocument${date}*" -name
$file3=gci "${filepath}\New3TextDocument${date}*" -name
$file4=gci "${filepath}\New4TextDocument${date}*" -name
$file5=gci "${filepath}\New5TextDocument${date}*" -name
$array=@($file1,$file2,$file3,$file4,$file5)
foreach ($i in $array) {
if ( -Not $i) {   
   Write-Host "<<< File missing >>>"
              }
else {Write-Host "File $i present"}
}