Changing UID/GID of VirtualBox

[sorcerer]

I am using Win10 pro with HyperV disabled. My app building environment on Win10 is Vagrant + VirtualBox. I installed Ubuntu inside Vagrant. The docker app I am trying to build requires me to create groups and users using specified uid=999 & gid=999.
When I tried to assign these ids to create groups using the “groupadd” command (after I Vagrant SSH in), I received an error saying 999 is already occupied by the other app on my platform. The other app so happened to be “vboxsf” which is VirtualBox. My setup is clean. This app in question is the only app I tried to setup in this Vagrant+Virtualbox setting.
I don’t think I can change the VirtualBox’s uid/gid inside this Vagrant+Virtualbox environment. If it can this change will be straight forward using the following command
sudo mount -t vboxsf folder share -o uid=1000,gid=1000
Is there a way I can change the UID,GID of VirtualBox on the Windows Host environment before I even install Vagrant so that I can build the app I mentioned in this Vagrant + VirtualBox configuration?
Thanks in advance.

[scottgus1]

Vagrant changes Virtualbox in ways we don't know. You'll have to ask them in the Vagrant forums.