At present in a blpackage, we can add only external commands(orders).
It would be possible in a near future to add commands(orders) of type nsh
The purpose would be to simplify some command(order)
under Windows to have the free space
wmic logicaldisk where space " 'DeviceID C C: ' " get FreeSpace
while by a command(order) nsh
ndf // <server>
You can run a native windows command in the ‘external command’ to get this info.