As far as I know the Bluetooth serial port protocol doesn't say anythng about port numbers.
You can connect to a remote Bluetooth serial port service (but you do not know what virtual COM port that might be on the remote device - if any at all).
You can let your BlueTools client that has connected to a remote Bluetooth serial port service be linked to a virtual COM port, but you don't need to do that to receive and send data. It is easier to just skip the COM ports.
If you have a legacy application that needs the COM port, and your mission is to do the linking between a COM port and the Bluetooth world, then you can use virtual COM ports, but that is the only case when you should.
If it is your application that is sending and receiveing data from a Bluetooth serial port service, then you should stop thinking about COM ports.
Start experimanting with the samples you find in the SDK, to see what is possible and not using BlueTools.
It is much better to think of Bluetooth as TCP/IP sockets than COM ports, it fits the model much better.