Error append line to excel file with powershell - excel

Question

I am getting error-messages, if i am running this code. I want to read users active directory data such as username, name, mail and append these informations to an xlsx file for license-tracking and ordering.
$user = Read-Host "Username"
$data = Get-ADUser -Identity $user -Properties * | select SamAccountName,AdminDisplayName,EmailAddress
$user = $data.SamAccountName
$name = $data.AdminDisplayName
$mail = $data.EmailAddress
$clo = Read-Host "Alter Computername (Nur bei Übertrag)"
$cln = Read-Host "Neuer Computername"
if ($clo -ne '') {
$out = "Übertrag: $($user), $($name), $($mail), Alter PC: $($clo), neuer PC: $($cln)"
}else {
$kst = Read-Host "Kostenstelle"
$out = "$($user), $($name), $($mail), PC: $($cln), KST: $kst"}
$excel_file_path = '"##PATHTOFILE#CENSORED#\test.xlsx"'
## Instantiate the COM object
$Excel = New-Object -ComObject Excel.Application
$ExcelWorkBook = $Excel.Workbooks.Open($excel_file_path)
$ExcelWorkSheet = $Excel.WorkSheets.item("Tabelle1")
$ExcelWorkSheet.activate()
## Find the first row where the first 7 columns are empty
$row = ($ExcelWorkSheet.UsedRange.Rows | ? { ($_.Value2 | ? {$_ -eq $null}).Count -eq 7 } | select -first 1).Row
$ExcelWorkSheet.Cells.Item($row,1) = 'COLUMN 1 Text'
$ExcelWorkSheet.Cells.Item($row,2) = 'COLUMN 2 Text'
$ExcelWorkSheet.Cells.Item($row,3) = 'COLUMN 3 Text'
$ExcelWorkSheet.Cells.Item($row,4) = "$out"
$ExcelWorkSheet.Cells.Item($row,5) = 'COLUMN 5 Text'
$ExcelWorkBook.Save()
$ExcelWorkBook.Close()
$Excel.Quit(
[System.Runtime.Interopservices.Marshal]::ReleaseComObject($Excel))
Stop-Process -Name EXCEL -Force

Answer 1

The following instruction does not return any value for $row for me:
$row = ($ExcelWorkSheet.UsedRange.Rows | ? { ($_.Value2 | ? {$_ -eq $null}).Count -eq 7 } | select -first 1).Row
I tried to browse the worksheet until a row where the first 7 columns are empty is found, using a loop. It seems to be working.
$lastrow = $ExcelWorkSheet.UsedRange.Rows.Count
for ($row = 1; $row -le $lastrow; $row ++) {
$test = $true
foreach ($col in 1..7) {$test = $test -and ($ExcelWorkSheet.Cells.Item($row,$col).Value2 -eq $null)}
if ($test) {break}
}