CSV p and p file

If all of the fields are constant width, perhaps a simple keystroke macro to return cursor to start of (next) line, move right N places until just past the Mix X value, insert " mil", move right until just past the Mid Y value, insert " mil", end (which will be followed by "return cursor to start of next line" when you reinvoke the macro.

If the eventual result is to make PCB with gerber files, then yes, just a couple of unit and scaling lines.

You can add the mil label as a format. It will show in the spread sheet cells and if someone manually copies those cells it is included in the text. Since I don't know exactly how they will use a spread sheet, I can't say this will work for them.

To do this select a cell or cells and right click to get the popup menu and select "Format Cells". Under category select Numbers and select an appropriate format under Format. Near the bottom of the dialog box put the text cursor in the Format Code line and type "mil" with the quotes. If you want the numbers to be fixed width fields you can use zeros to force the number length with leading and trailing zeros. For example 0000.00"mil" results in the fifth field in the first line being "3181.15mil" while 00000.00"mil" would give "03181.15mil".