Selections from existing files can't be incremented

[AlexSCFraser]

Hi, I love the plugin! Thank you for putting it together, as I find myself incrementing sequences all the time. One small thing is that if I want to increment a sequence which already exists in a file or maybe something I copy/paste en mass between files, the increment command doesn't work. If I then reselect all the sequences, delete the last number, replace the last number with a zero or whatever the smallest number in that position of my sequence is, then use the command, it works and I can increment the existing sequences. But it would be a lot simpler if the plugin could increment a multiple selection of preexisting sequences without having to delete and reenter the last digit or character.

This isn't really a bug, since the description clearly states that the plugin is designed to add numbers to selections, but it seems like an obvious use for such a command and it's so close to being able to do this in one command.