Hi betsmart,
I was just developing something similar, also based on volume.
Try the following! First create 3 custom cells (Settings/Excel):
1.) Cell Address: S15:1 Cell Value: volume
2.) Cell Address: S16:1 Cell Value: =RANK(O(sel_index*3+1),O4:O100,0)
3.) Cell Address: S17:1 Cell Value: =RANK(O(sel_index*3+1),O4:O100,1)
That means you have to connect MFPro to Excel to make this trigger work.
Then just open the enclosed trigger and it might do the job.
I haven't tested it. Please give me your feed back.
Cheers,
bamthwok