multiple instances of ITC objects in CMSIS-RTOS

Hello,

I'd like to write some reusabel code module to handle e.g. UART ports. Therefore I'd like to create a variable number (based on some kind of define...) of threads dealing with UART port 1,2,3 ... since it is possible to declare CMSIS-RTOS threads with a variable number of instances it could look like this:

#define UART_PORT_NUM 3

osThreadDef(uart_thread, osPriorityNormal, UART_PORT_NUM, 0)

my problem: If I need any kind of inter-thread communication (ITC) object, like mutexes or mail queues, for each of this threads I don't know how to declare them, since osMailQDef, osMutexDef and so on, are not designed with a "variable" number of instances...

Any suggestions?