Calling Tilemap PositionToTileX and PositionToTileX from script

I tried to make a script that would convert the mouse position to the corresponding tilemap tile, if it were an edvent I'd use PositionToTileX and PositionToTileY but turns out those functions aren't available from javascript, they're not in the documentation and I can't find any replacement for these, how would I use these functions without having to make a whole eventsheet function for it?

Here is a quick exmaple of how i have done the conversion in the past

here is the c3p file

https://drive.google.com/open?id=1SeUkVyk3SzIXhc5UNTBOXW-55ldiE1yp

Thank you, that was a nice solution