I have a simple data conversion tool and one of the outputs it can produce is a csv file.

This works perfectly here in the UK but when I shipped it out to a German customer I had some issues. Specifally, they use a ',' to represent the decimal point in a floating point number and vice versa. This means that when they open their data file in excel, the result is rather messy to say the least :-)

Substituting the correct character is trivial, but how can I detect whether or not to apply this?

Edit:

So this:

a,b,c
1.1,1.2,1.3
"1.1",1,2,"1,3"
"this,is,multi-
-line",this should be column 2, row 4
a;b;c
"a;b","c"

..looks like this when loaded into excel in the UK:

+----------------+-----+-----+-----+
| a              | b   | c   |     |
+----------------+-----+-----+-----+
| 1.1            | 1.2 | 1.3 |     |
+----------------+-----+-----+-----+
| 1.1            | 1   | 2   | 1,3 |
+----------------+-----+-----+-----+
| this,is,multi- |     |     |     |
| -line          | 2   | 4   |     |
+----------------+-----+-----+-----+
| a;b;c          |     |     |     |
+----------------+-----+-----+-----+
| a;b            | c   |     |     |
+----------------+-----+-----+-----+

..but what happens in Germany?