Abstract Document Attributes

I'm a PowerShell noob.

I have a look-up table wherein there is an Attribute called PW_Email. Ultimately, I want to capture the value of that attribute as a variable in a FOREACH.

Here's my FOREACH so far:

FOREACH ($i in $lookuptable) { $Document = Get-PWDocumentsByGUIDs -DocumentGUIDs $i.DocumentGUID }

So, $Document.Attributes then returns:

Key                 Value
---                     ----
PW_Email       JDoe@ACME.com

I think I need to finish the following to include in the FOREACH::

$EmailAddress = $Document.Attributes.Where(

Am I close? Can anyone help me to fill in the blanks?

Thanks in advance for any help,