At my company we have a 3rd party app which tracks off-hours duty for all of our engineers. The app is not web-enabled and we cannot make any changes to it. It does write a simple text file and I have created an app that translates that to an ICS file. My goal is to have that appear on my calendar on my Android phone. Here is the path I am working on:

DutyApp --> TextFile --> ICSFile --> Outlook(exchange) -- > Android (via exchange sync)

My problems: If I place the ICS file on our FILE server and then in Outlook if I go to the option Calendar>Open Calendar>From Internet it shows up in Outlook and looks pretty good. After a couple minutes it shows up on my Android phone as well. If I change the original ICS file those changes never display in Outlook and never sync to my Android phone. This seems to be a one shot deal almost like an import.

Now if I place the ICS file on our WEB server and then in Outlook if I go to the option Calendar>Open Calendar>From Internet and use webcal:\ as the address, it shows up in Outlook and also looks pretty good. Any changes I make to the original ICS file display in Outlook. However the entire calendar never shows up in Android. This calendar is a subscription and it seems, although am not sure, that Android doesn't display Exchange subscription calendars. Yes I know it works with Gmail subscription calendars but this is Exchange.

So my question is what other options are there? We are behind a firewall so cant link the ICS file to a Gmail account. I can't put the ICS file anywhere else other than our file or web server.