No Environ("password") for Active Directory User Binding?

Question

I want to reuse the Windows authentication to bind to the Active Directory user and check group membership.

I can get the Windows username with Environ("username"), but how do I get the password? I don't want to have to require the user to reenter their password, but there is no Environ("password").

How do I make this code work?

Thanks!

Private Sub ADsAuthenticate()

    Dim objConnection As New ADODB.Connection
    Dim objRecordset As ADODB.Recordset
    Dim objADsUser As IADsUser
    Dim objADsGroup As IADsGroup
    Dim strUsername As String
    Dim strPassword As String

    strUsername = Environ("username")
    strPassword = Environ("password")

    With objConnection
        .Provider = "ADsDSOObject"
        .Properties("User ID") = strUsername
        .Properties("Password") = strPassword
        .Properties("Encrypt Password") = True
        .Open "ADs Provider"
        Set objRecordset = .Execute("<LDAP://<server>/dc=<domain>,dc=com>;" _
        & "(sAMAccountName=" & strUsername & ");ADsPath;Subtree")
    End With

    With objRecordset
        If Not .EOF Then
            Set objADsUser = GetObject("LDAP:").OpenDSObject(.Fields("ADsPath").Value, strUsername, strPassword, ADS_SECURE_AUTHENTICATION)
            Debug.Print objADsUser.ADsPath
            For Each objADsGroup In objADsUser.Groups
                Debug.Print objADsGroup.Name
            Next
        End If
    End With

    objConnection.Close

End Sub