Marlin is just firmware. But when you connect to windows you should see in hardware manager a com port appear or an unknown device, in which case you need to install the driver.
For malin see here
https://marlinfw.org/<br/><br/>Hope you have already marlin installed. But I don't know blue box so can not say as what it appears.
Once you get com port you can connect host with it secting right baud rate and ascii or automatic protocol.
Eslcam must then produce gcode for marlin and you can load that into host to send it. But you might like need to first home or calibrate position. Thats something I can not help with as it depends much on what you have as sensors and firmware configuration.
