Yeah, but that has to happen when his customer opens the workbook. The OP is looking for something he can put in that cell that'll handle the problem automatically, without the recipient having to do anything special.

I've never done this, but in at least the more recent versions of Excel I've seen an option that defines whether cell values in .csv files are store with quotes always, sometimes or never. I wonder whether setting that to Always (at your end) would result in the value "03" with quotes, and whether it would then read in as you want it at the other end?