How to avoid COM0 when a 4 port USB to serial port hub is connected

I am attaching a 4 port USB to Serial hub on to the USB port of Colibri iMX6 module (WEC7). The problem is, it becomes COM0, COM4, COM5, COM6.

I need them to be ordered from COM4 to COM7. or COM7-COM10 etc. How to achieve that? It seems COM0 is not used and it fills up first.

Another thing is, we are planning to add a 8 port USB to serial hub later. What we noticed is if the port number goes beyond COM9, it becomes /device/COM10 instead of COM10. How to fix number over 10?

Dear @marifhossain

To start with a higher index, check whether your USB-to-serial driver offers a suitable registry setting.
FTDI for example controls this through the setting:

InitialIndex = 6

to start numbering at COM6.

In Windows CE it is not possible to address two-digit COM ports with the simple notation like COM12. You always need to use the long name $device\COM12 instead.
However, you can use this long name also for one-digit COM ports like $device\COM2.

Regards, Andy