How to Set the Proxy Internet Ip address for Anti Malware filter in Exchange Server 2013

Hi all

Recently I have installed Exchange 2013 Mailbox Server , i have planned to enable the Malware filtering , I followed the steps and enabled the Malware filtering , the problem is , i don`t want to give the direct internet connection to the server , i want to configure the Engine Updates download to be download via the proxy server , anybody give the details , how to customize the Anti Malware Engine to allow the proxy ip address to download the updates.

Thanks

Viswa