This is a nice feature that TextPad has:
When inserting, replacing or deleting (with backspace), and then changing line with up or down arrow the cursor will be positioned on the column where the action began. This allows fast replacements or insertions of secuences on multiple lines.
Here is an example. With the following text, supose that we would like to prefix the line number with zero:
1. Item one
2. Item two
3. Item three
So the final result will be
01. Item one
02. Item two
03. Item three
Currently in order to do it, we should position the cursor on the first column of the first line, then press zero, then press down arrow, and press left arrow to reposition on the first column.
With the proposed feature, it won't be necesary to press left arrow, since the editor will remember the position before the inserting.