Are you talking about the Internet headers for an e-mail?
If so, you need to use CDO to read the value of PR_TRANSPORT_MESSAGE_HEADERS
from a Field object, or use Redemption (
http://www.dimastr.com).
If you have Outlook 2007, you can use VBA:
Sub DemoPropertyAccessorGetProperty()
Dim PropName, Header As String
Dim oMail As Object
Dim oPA As Outlook.PropertyAccessor
'Get first item in the inbox
Set oMail = _
Application.Session.GetDefaultFolder(olFolderInbox).Items(1)
'PR_TRANSPORT_MESSAGE_HEADERS
PropName = "
http://schemas.microsoft.com/mapi/proptag/0x007D001E"
'Obtain an instance of PropertyAccessor class
Set oPA = oMail.PropertyAccessor
'Call GetProperty
Header = oPA.GetProperty(PropName)
Debug.Print (Header)
End Sub