Hi Michael,

>> say you have just the box selected, and now you want to select
>>all curves in addition to that. It won't work for that since it will take
>>the box as the example right away...

Hmmm... If I linked that custom command to the icon/button, I guess it could be solved. The first click on icon/button would start command as if there was no preselection allowed, it means the command prompt would pop-up and wait for picking an object, but the second click on icon/button would lead to resuming command using pre-selected object - similar to how command Hide works :)

Petr