Arguments:
- _mode,"name1","name2",...
Description:
Return the set of indices corresponding to images of the selection with specified names.
After this command returns, the status contains a list of indices (unsigned integers),
separated by commas (or an empty string if no images with those names have been found).
(equivalent to shortcut command nmd).
mode can be
{ 0=all indices (default) | 1=lowest index | 2=highest index | 3 = all indices (case insensitive) | 4 = lowest index (case insensitive) | 5 = highest index (case insensitive)}