Here is something you can look at, not sure it's what you were looking for , but there might be something there for you. I was working on it and finished before I saw you got what you needed.
// Will return the center of the specific tileset tile the OWaypoint object is located
vector TileCenter(object oWaypoint)
{
vector vWaypoint = GetPosition(oWaypoint);
float fX,fY;
float fX = vWaypoint.x;
float fY= vWaypoint.y;
// Store the decimal value if fX
float fX1 = fX-FloatToInt(fX);
// Get the value of the ones column of fX
int iX1 = FloatToInt(fX)%10;
// The x coordinate within the specific tile
float fX2 = fX1+iX1;
// The x value for the distance to the center of the specific tile from the oWaypoint object
float fX3 = (((10.0-fX2)-fX2)/2)+fX2;
// The x value for center of the tile the oWaypoint object is located within the global environment
float fX4= fX-fX2+fX3;
// Store the decimal value if fY
float fY1 = fY-FloatToInt(fY);
// Get the value of the ones column of fY
int iY1 = FloatToInt(fY)%10;
// The y coordinate within the specific tile
float fY2 = fY1+iY1;
// The y value for the distance to the center of the specific tile from the oWaypoint object
float fY3 = (((10.0-fY2)-fY2)/2)+fY2;
// The y value for center of the tile the oWaypoint object is located within the global environment
float fY4= fY-fY2+fY3;
return Vector(fX4, fY4, 0.0);
}
