How to create a dimmer entity via node red?

i hava a light fysicly that use , ant the brightnes i control it via rs232.
i can make a flow in nodered , ant control it via my serial port ( light on , off , brighness , status , etc) .

now i want in homeassistant this icon to use : Light Card - Home Assistant

but how can i make nodered to create a dimmerentity in homeassitant ?

so i can control the dimmer-card , and in the background nodered is sending the serial data ?