uC UART to BLE to PORT COM

What I want to do is get data from a Main board (Custom uC with sensors) via UART and connect it to the UART set pins (29 and 31) of a nrf52840 dongle. This in turn will send the information to a DK nrf52840 via bluetooth and the DK nrf52840 will be connected to the COM port of a laptop to view the data on a serial terminal. I want both (DK and dongle to connect automatically). I want to make this link since the main board and the dongle will be in a place of difficult access and through the ble link with the DK I will be able to observe the data in a safe place.