def start_at(x, y=0)
      from.coord x, y
    end
sets the starting position for the anchor.
You can provide a String like "A1", an array like [0,0] or a cell object for the x parameter.
We just 'figure it out' for you.
@param [Array, String, Cell, Integer] x Accepts many inputs for defining the starting position of the cell.
@param [Integer] y When x is an integer, this value is used for the row index at which the anchor starts.