manually put custom mark(er) on map menu

[kucingkucing]

you know, when in the map menu you can put the default map marker (the green one) with the right mouse button,

and if you hold about half to 1 second, the option with appear, and you can choose 3 different map marker,

the red skull, the blue triangle, and the orange exclamation mark (!),

I looking for this function for two days and found nothing,

so, my questions are :

 

1.can someone tells me where this function is

2.if point number 1 does not exist, can someone make it for me, this the script of my idea:

exec function addCustomMarker(mapname : name, x : float, y : float, symbol : int)
{
	// mapname is map area like white orchard, novigrad(include velen and oxenfurt), skellige, and toussaint).
	// x and y is coordinate.
	// and symbol are : 1 = red skull, 2 blue triangle, 3 yellow exclamation mark.

	THE CODE

}

exec function removeCustomMarkers()
{
	// remove all custom markers

	THE CODE

}

I don't know if this code can be done or not, I hope I can get a clue how to do it,

thanks for read, sorry for my bad English, and have a nice day.