# Convert each sheet of an .xlsb workbook to CSV using Excel COM, with macros force-disabled.
param([string]$InFile, [string]$OutDir)
New-Item -ItemType Directory -Force $OutDir | Out-Null
$OutDir = (Resolve-Path $OutDir).Path
$xl = New-Object -ComObject Excel.Application
$xl.Visible = $false
$xl.DisplayAlerts = $false
$xl.AutomationSecurity = 3   # msoAutomationSecurityForceDisable
try {
  $wb = $xl.Workbooks.Open((Resolve-Path $InFile).Path, 0, $true)
  $n = $wb.Worksheets.Count
  $names = @(); for ($i = 1; $i -le $n; $i++) { $names += $wb.Worksheets.Item($i).Name }
  for ($i = 1; $i -le $n; $i++) {
    $ws = $wb.Worksheets.Item($i)
    $ws.Activate()
    $name = $names[$i-1] -replace '[^A-Za-z0-9_-]', '_'
    $out = Join-Path $OutDir ("$name.csv")
    $wb.SaveAs($out, 62)   # xlCSVUTF8 saves active sheet
    Write-Output "wrote $out"
  }
  $wb.Close($false)
} finally {
  $xl.Quit()
  [System.Runtime.InteropServices.Marshal]::ReleaseComObject($xl) | Out-Null
}