Extrapolating a line between two points

I am plotting a line using bresenham algorithm between two points. How can I extend (extrapolate) that line? e.g I am plotting a line between points (0,2) and (4,10) using bresenham algo. I want the output plot be the extrapolated line between (0,2) and (8,y).

Any help will be appreciated

[Mahi Nazir]

Since I am using bresenham algo, I am plotting each point along the line.