How do i create a virtual folder in my microsoft/aspnet:4.7.1-windowsservercore-1709 image

I have this simple default Dockerfile that i'm using:

FROM microsoft/aspnet:4.7.1-windowsservercore-1709
ARG source
WORKDIR /inetpub/wwwroot
COPY ${source:-obj/Docker/publish} .

And i'm trying to publish my in a subfolder in wwwroot, because my application is hardcoded to use a virtual folder, but it seems this is outside the scope of Docker's capabilities. At least for Windows.

If i try things like changing the WORKDIR to /inetpub/wwwroot/subfolder, it fails bringing up the app with:

Recreating dockercompose16651484078226882483_dotnetwebappdocker_1 ... Recreating dockercompose16651484078226882483_dotnetwebappdocker_1 ... error ERROR: for dockercompose16651484078226882483_dotnetwebappdocker_1 Cannot start service dotnetwebappdocker: container e6d05a411cb22028ab2a855eaafdfab541f81f3b47ebe7255ee5ddcd31b774f9 encountered an error during Start: failure in a Windows system call: The compute system exited unexpectedly. (0xc0370106) ERROR: for dotnetwebappdocker Cannot start service dotnetwebappdocker: container e6d05a411cb22028ab2a855eaafdfab541f81f3b47ebe7255ee5ddcd31b774f9 encountered an error during Start: failure in a Windows system call: The compute system exited unexpectedly. (0xc0370106) Encountered errors while bringing up the project..

Ultimately i want to publish two applications in my wwwroot, an /app/ and an /auth/ but i need one to work before adding another :)

Any help out there?