Hi Igor,
In your case, below may seem obvious but thought I would just mention...
If I understand you correctly, just create a progress bar. You can find examples in Klaus' examples:
Loading Progress and
Video-Panorama.
For a clock or pie graphic, my solution was to produce a series of graphics, each representing a 5% change. These are assembled into one long png file. The graphic you display in the layer or hotspot is a crop of that png showing one pie/clock face. Then use your delayed call action to find the percent completed. Every n% you simple change the crop to the corresponding pie/clock face.