You could do the following , you would think there would be an easier way but there doesn't seem to be a command to retrieve mouse co-ordinates.
Declare global variables.
float mouseX=0;
float mouseY=0;
Then in your main loop.
mouseX=mouseX+dbMouseMoveX();
mouseY=mouseY+dbMouseMoveY();
dbPositionMouse(mouseX,mouseY); // wont work properly without this
dbPrint(mouseX);
dbPrint(mouseY);
You might want to limit the movement to your screen size.
You can use dbRotateSprite to turn your character.
You may need to use a bit of trigonometry to find the angle for your character to face.