I am trying to load an excel addin from my bloomberg finance software with powershell and i am at a loss. i can open excel manually and the add ins load but using powershell i get a "Exception calling "Add" with "2" argument(s): "Add method of AddIns class failed" error when calling only the com add-in dlls, the xla excel add in appears to work. Does "applications.addins.add only work for xla files and not dlls(comaddins)? heres my script

$strPath="\\domain.com\homeoffice\divisions\Finance\960\Shared\reportsPeriodic\trr.xlsx"
$objExcel=New-Object -ComObject Excel.Application
$objExcel | get-member
$objExcel.Visible=$true
$ExcelWorkbook=$objExcel.Workbooks.Open($strPath)
$ExcelAddin = $ExcelWorkbook.Application.AddIns.Add("c:\blp\api\office tools\BloombergUI.xla", $True)
$ExcelAddin.Installed = "True"
$ExcelAddin = $ExcelWorkbook.Application.AddIns.Add("c:\blp\api\office tools\bofaddin.dll", $True)
$ExcelAddin.Installed = "True"
$ExcelAddin = $ExcelWorkbook.Application.AddIns.Add("c:\blp\api\office tools\Bloomberg.Taskpane.Host.dll", $True)
$ExcelAddin.Installed = "True"
$ExcelAddin = $ExcelWorkbook.Application.Addins.Add("c:\blp\api\activex\ccycodes.dll", $True)
$ExcelAddin.Installed = "True"
$worksheet = $ExcelWorkbook.sheets.item(1)