Stop truncating / dropping leading zeroes when opening csv file
You have 2 options:
To import a CSV file without deleting zeros (or changing anything at all actually):
1) Open a blank excel sheet.
2) Select all cells (CTRL+a) and format them as text (right click->format cells).
3) Open your CSV in notepad (you can do so by dragging the file into an open notepad window).
4) Copy all of the content of the CSV and paste it into the first cell in excel. Notice that a "Paste Options" icon appears somewhere at the bottom.
5) Click on the small arrow on the right of that icon, and select "use text import wizard". This will open a wizard...
6) Make sure "delimited" is selected and click "next"
7) Select "comma" and deselect "space" in the delimiters area (you will see the columns arrange correctly in the sample below), then click "next".
8) In this step you define how to treat each column. Since we don't want excel to change anything, we'll define them all as "text": Click on the first column in the sample (it will be colored in black); now scroll sideways all the way to the right and shift+click the last column; in "column data format" above, select "text".
9) Click "finish".