I think you are out of luck, I don;t think you can download it from anywhere else.
- Download Windows apps for your Windows tablet or computer. Browse thousands of free and paid apps by category, read user reviews, and compare ratings.
- Get the Remote Desktop client. Follow these steps to get started with Remote Desktop on your Mac: Download the Microsoft Remote Desktop client from the Mac App Store. Set up your PC to accept remote connections. (If you skip this step, you can't connect to your PC.) Add a Remote Desktop connection or a remote resource.
Download this app from Microsoft Store for Windows 10 Mobile, Windows Phone 8.1, Windows Phone 8. See screenshots, read the latest customer reviews, and compare ratings for VLC Mobile Remote: PC & Mac.
Maybe also look into http://cord.sourceforge.net
Why don't you try downloading it on your computer and see if you can extract the file from the download? Right-click and show package content.
Apple Store Microsoft Rdp
PS: Is that: https://www.microsoft.com/en-us/download/details.aspx?id=465 the right client?
I can't test it since I don't have a MAC at work.
or this one: https://www.microsoft.com/en-us/download/details.aspx?id=18140
Microsoft Store Remote Desktop App Download
Edited Apr 21, 2015 at 22:53 UTC