GetActiveDirectoryName(strDomain, strUser)

Public Function GetActiveDirectoryFullName(strDomain As String, strUsername As String) As String
' http://www.utteraccess.com/wiki/index.php/GetActiveDirectoryName
' Code courtesy of UtterAccess Wiki
' Licensed under Creative Commons License
' http://creativecommons.org/licenses/by-sa/3.0/
'
' You are free to use this code in any application,
' provided this notice is left unchanged.
'
' rev  date        brief descripton
' 1.0  2013-01-30  Initial Release
'
   'Connect to Active Directory
   Dim cnn As Object 'ADODB.Connection
   Set cnn = CreateObject("ADODB.Connection")
   
   cnn.Provider = "ADsDSOObject"
   cnn.Open "Active Directory Provider"
   
   'Create the query
   Dim strSQL As String
   strSQL = "SELECT distinguishedName" & _
            " FROM 'LDAP://" & strDomain & "'" & _
            " WHERE objectCategory='user'" & _
                  " AND samAccountName = '" & strUsername & "'"

   'Get the data and return the result
   Dim rst As Object 'ADODB.Recordset
   Set rst = cnn.Execute(strSQL, , 1)

   If Not rst.EOF Then _
       GetActiveDirectoryFullName = Split(Mid(rst.Fields("distinguishedName"), Len("CN=") + 1), ",")(0)

   'Close what we open.
   rst.Close
   cnn.Close
   
End Function

? GetActiveDirectoryFullName("someDomain","someUsername")
someFirstname someLastname