How do I select tiles in the Red Alert scenario editor?

[SmegmaLasagna]

 

I want this pillar to cast a shadow on the road but it will have a roadtile underneath it. To solve this I would just have to copy and paste the upper tile from the other version, however I can not seem to find out how to select any tiles.

[Ford (retired)]

Hold Alt+Left Click the tile, Alt+Left Click somewhere else to select multiple titles. Ctrl+Insert is to copy the selection, Shift+Insert to paste.

Alt+Right Click removes your current selection.

[Jacob Foerster]

I also think right click and hold on the tile allows you to drag it around if I'm not mistaken.