The feature to paste a single line text in clipboard into all lines with a selected column in column mode was introduced with UltraEdit for Windows v24.00 and is perhaps not yet available in UltraEdit for Linux. I use only UltraEdit on Windows and so cannot verify that.

I wrote a little UltraEdit script for this purpose, see Scripts to insert/fill strings from clipboard into selected columns in column mode. It was tested by me only with all versions of UltraEdit for Windows with support for scripts. So I don't know if this script works also with UEX or UEM.

There is of course also the possibility to click in menu Column on menu item Insert/Fill Columns... or execute this command by hotkey, paste the string in clipboard into the edit field and click on button OK or press key RETURN to fill the selected columns with string in clipboard. I suppose that UltraEdit for Linux has this command because of this command exists since I use UltraEdit (more than 20 years).

The UltraEdit Linux complete feature list has just the list item Active line highlighting while UltraEdit Windows complete feature list has the list item Active line and active column highlighting. So it looks like UEX v18.00 does not support active column highlighting. In UltraEdit for Windows there is in Manage Themes dialog on tab Editor the check box item Enable active column highlighting. I suggest to look in Manage Themes dialog of UltraEdit for Linux if there is also such a check box item respectively in dialog window opened by clicking in menu View on item Set Colors... if UEX has no support for themes until now as it looks like after searching the features list of UEX for the word theme.

Please take into account that UltraEdit was not written from the beginning as multi-platform text editor using Java or libraries available for Windows, Linux and Mac. UltraEdit was written more than 15 years just for Windows. Then IDM Computer Solutions, Inc. has started porting to other platforms the code written natively just for Windows using the libraries written by Microsoft for Windows. So Windows version of UltraEdit is always ahead regarding to available features. Further I suppose that there are much more users purchasing licenses for UltraEdit for Windows than for UltraEdit for Linux. So a company like IDM Computer Solutions, Inc. paying their employees with money earned by selling licenses focus most likely the development on the platform on which getting more return of investment. I recommend to study the features list of UltraEdit for Windows and for Linux to find out which features are not supported yet by UltraEdit for Linux. I hope the features list of UEX and UEM are as accurate as the one of UltraEdit for Windows.