MC TL GetActive
trendline ID number of the currently selected trendline; returns a value of -1 if no trendlines are currently selected.
- A trendline-specific ID number is assigned by MC_TL_New when the trendline is created.
Assign a value, indicating the trendline ID number of the currently selected trendline, to the Value1 variable:
Value1 = MC_TL_GetActive;
At this link, there is an base logic that shows how this command can allow MC to receive interactive user input. You can adapt it to your specific needs. http://www.multicharts.com/discussion/viewtopic.php?f=5&t=7764