Get thumbprint of a certificate

All you have to do is wrap the command in parentheses, and then use dot-notation to access the Thumbprint property.

Try this out:

$Thumbprint = (Get-ChildItem -Path Cert:\LocalMachine\My | Where-Object {$_.Subject -match "XXXXXXX"}).Thumbprint;Write-Host -Object "My thumbprint is: $Thumbprint";

If you get multiple certificates back from your command, then you'll have to concatenate the thumbprints into a single string, perhaps by using the -join PowerShell operator.

$Thumbprint = (Get-ChildItem -Path Cert:\LocalMachine\My | Where-Object {$_.Subject -match "XXXXXXX"}).Thumbprint -join ';';Write-Host -Object "My thumbprints are: $Thumbprint";

You can use Select-Object to get only the Thumbprint-property:

Get-ChildItem -Path Cert:\LocalMachine\My |     Where-Object {$_.Subject -match "XXXXXXX"} |     Select-Object -ExpandProperty Thumbprint

Get-ChildItem -Path Cert:\LocalMachine\My | Where-Object {$_.Subject -match "XXXXXXX"} 

This one will never work cause you are using $_.subject you shall use $_.thumbprint:

Get-ChildItem -Path Cert:\LocalMachine\My |  Where-Object {$_.Thumbprint -match "0F273F77B77E8F60A8B5B7AACD032FFECEF4776D"}