Excel 2007 : Score the similarity of the characters between several cells

Hi people!!

I'd like to give a "similarity" score to each code from a list of 4-digit codes:

1321
1311
1311
3533
4925
1389
4922

If one of the codes has the same first 4 digits than another code, it will receive a score of 4. If it has the same first 3 digits, a score of 3, and so on until 0.

The result of the above list should resemble to this:

1321 2
1311 4
1311 4
3533 0
4925 3
1389 2
4922 3

Is it possible using an Excel formula?

Your help is very much appreciated!