Data Plots Generate Plot Graph with Solid / Dash Line

I am trying to plot a graph using VBA and have generated the plot. It is a line graph, I'm connecting the points (below) with a line, however I would cells 1, 2 and 3 to be connected with a solid line and points 3 and 4 to be connected with a dash line.

1 23
2 32
3 25
4 44

I am trying to use VBA to do this, because I have an If Statement which chooses which points should be connected with a dash and which points should be solid.

Any thoughts to get my started or if this is even possible would be greatly helpful. Thanks