I used to use KVM to do this because I can run any Windows Application installed on the Windows VM on my Ubuntu Desktop in a gnome window just like any other Linux Application.
I can move/resize, minimize, maximize the Windows application just like any linux app.
I use xfreerdp to start the RemoteApp process and as part of that i specify on the xfreerdp command for Windows to have access to a shared directory on my Ubuntu Host, to enable sound, Clipboard etc etc.
The command is executed in a normal Terminal and looks much like this:
$ xfreerdp /cert-ignore /u:winUserID /p:winPasswd /drive:shared-folder,/home/bmullan/shared-folder +clipboard /sound:sys:alsa /app:‘%windir%\explorer.exe’ /v:10.43.209.134
Where: 10.43.209.134 is the IP address of my Windows 7 LXD VM.
Using LXD to create the Window’s VM works so much better and transparently than before and its much faster.
Stephane Graber had written some steps to create a Windows 10 LXD VM but I never liked Win10 and for my use-case don’t need it as Windows 7 can run all the applications I’m interested in. But going that route I had to learn alot of config steps not mentioned in Stephanes Win10 VM guide.
None of it is hard but took many trial and errors by me to figure out what I needed to do.
Now looking back its really pretty straight forward so i hope documenting it all will be easier.
I’m writing up the config/installation steps you would need to follow to do this yourself.
I think everybody has some “windows” app they’d like to use but it does not run or run well in Wine and if you create a Traditional Windows VM you end up with not just a One Application Window but the Whole Windows Desktop to deal with. This just runs the Windows application itself in its own window.
I also tested and I was able to clone/copy my initial LXD Windows 7 VM, start it and everything (remoteapp capabilty) still worked perfectly.
I am amazed!
I figured the LXD linux VMs would work well but wasn’t so sure how far I’d get with an LXD Windows VM (Windows 7 Ultimate in my Case).
Thanks so much Stephan, TomP, Simos et al.
I started the documenting but it may take a week so I can make sure I don’t forget steps 
Brian