How to draw a random point on a specific line within a specific boundary.

Let the

         XY_BOUNDARY = [0,70,0,50};
         position = [XY_BOUNDARY(2) - XY_BOUNDARY(1); XY_BOUNDARY(4) - XY_BOUNDARY(3)] .* rand(2,1) ...
               + [XY_BOUNDARY(1);XY_BOUNDARY(3)];

In the above code i get a random number within the specified boundary. Now i want the random point position in a specified boundary as well as on the line connecting two points (x1,y1), and (x2,y2, which are also present within the defined boundary...Please tell me how to do this

[Melanie Schmocker]

Are (x1,y1) and (x2,y2) already stored in your code and you want to find a point on the line between them? Or do you want to generate them randomly from within the boundary and then select a random point on the line between them?

If they're already stored in your code, are they guaranteed to be within the boundary?