Customer's Email in Order Confirmation Email

How to i have the customer's email be in the "From:" in the Order Confirmation Email? More clearly, when a customer order 2 confirmation are sent out, one to the customer with From: = [email protected] To: [email protected], and the other one goes to the admin with From: = [email protected] To: [email protected]. How do i change the From: = customers_email_address To: = [email protected]??? What i mean is to have the copy of the order confirmation email to the admin with the From id is the customer email address so that when I hit reply it will automatically input the customer's email into the To: box.
Is that clear or have i make it even more confusing? Help me!

in /includes/functions/functions_email.php
around line 219 (v1.3.8) you'll see this:$email_reply_to_address = ($email_reply_to_address) ? $email_reply_to_address : (in_array($module, array('contact_us', 'tell_a_friend')) ? $from_email_address : EMAIL_FROM); $email_reply_to_name = ($email_reply_to_name) ? $email_reply_to_name : (in_array($module, array('contact_us', 'tell_a_friend')) ? $from_email_name : STORE_NAME);add 'checkout_extra', as shown:```
$email_reply_to_address = ($email_reply_to_address) ? $email_reply_to_address : (in_array($module, array('contact_us', 'tell_a_friend'[B], 'checkout_extra'[/B])) ? $from_email_address : EMAIL_FROM);
$email_reply_to_name = ($email_reply_to_name) ? $email_reply_to_name : (in_array($module, array('contact_us', 'tell_a_friend'[B], 'checkout_extra'[/B])) ? $from_email_name : STORE_NAME);

Or you could just use your Admin area instead, and send email to the customer directly from the order page, including shipping status updates, tracking numbers, etc. This would keep all the info about the order in one place, online, accessible directly by the customer from their My Account area.