Is there text editor which treats letters and unoccupied space as cells and allows to copy any rectangular area to any place? Somewhat like Excel, but with one cell for letter.
Text editors SynWrite (Windows) and CudaText (cross platform) can do this. In these, you have "column selection mode", Alt+mouse drag. which selects rect block.
Note: To select also end of lines (where caret cannot go), turn on option "caret_after_end" in CudaText (and "Allow caret after end of line" in SynWrite).