I think that column mode is where you can select columns of text instead of rows. It is already there, but it's different than toggling it on and off like in Crimson Editor.
Press the "ALT" key while selecting the text and it selects columns.
This has been requested quite a number of times. As a matter of fact CTzen posted the following link UltraEdit Example in one of those other threads to demonstrate the requested feature.
I too, would like this to be implemented as it obliviates the need for a text editor next to PLD.
Edit: As I'm currently behind some obscure firewall thingy I could not check if the link is still working.
You have a column mode when using the Alt key, which allows operations like cut, copy, paste, and so on. It just does not support typing in multiple lines simultaneously, but for that you can easily use the Macro recorder.