Ok, but that didn't answer my question. In your original example, where you said the result should be 8, you seem to be suggesting that:

EQR/G/022/02/14, EQR/N/020/02/14, EQR/S/007/02/14, EQR/G/019/02/14, EQR/N/023/02/14, EQR/G/040/02/14

should all be counted since they are the "same pattern", though they are clearly not identical.

So please explain on what basis two strings should be considered to have the "same pattern".

Regards