Along the same lines, to have a dot (or any png image) track along a route...
Create the png or download it from the WEB.
Load it and your map or video into VP, with the map on track one and image on track two. Drag the right border of the image track to make it the same length as the track one.
Click the fx button on the image track. The effects window opens. (Under the preview window, click the chevron to the right of the VIEW icon and choose Clip & Background.)
Click the large green + sign at the left of the toolbar and choose the MOTION effect.
Use the SCALE field to size the image (in this case, a red dot) as desired.
With the scrubber (the red line in the effects window) positioned at the far left, drag the dot in the preview screen to the start of your route.
Click the small green + sign on the toolbar to set the first keyframe.
Move the scrubber to the right by a grid square or so (no need to be precise), then drag the dot to the desired next position. This sets keyframe two.
Repeat this action along the path you want to take until you reach the end point. (If the dot won't drag to where you want it, use the Horiz/Vert/Base sliders.)
The closer the keyframes are to one another, the faster the action is between them. You may need only a few keyframes, depending upon the route and its length.
If you make a mistake, press <ctrl-Z> to backtrack step-by-step.
The result will resemble this...
tracking.mp4