Python automated Outlook email: change sender or default reply-to address

I'm using code similar to Steve Townsend's answer from this question: Send Outlook Email Via Python? to send an email by running a python script. How can I edit the default reply-to address, so that when someone replies to the automated email it will get sent to a specific address? Alternatively, can I modify the address that the email is sent from? I tried to modify the Msg.SentOnBehalfOfName property but had no success with that.

import win32com.client

def send_mail_via_com(text, subject, recipient, profilename="Outlook2003"):
    s = win32com.client.Dispatch("Mapi.Session")
    o = win32com.client.Dispatch("Outlook.Application")
    s.Logon(profilename)

    Msg = o.CreateItem(0)
    Msg.To = recipient

    Msg.CC = "moreaddresses here"
    Msg.BCC = "address"

    Msg.Subject = subject
    Msg.Body = text

    attachment1 = "Path to attachment no. 1"
    attachment2 = "Path to attachment no. 2"
    Msg.Attachments.Add(attachment1)
    Msg.Attachments.Add(attachment2)

    Msg.Send()