Rename file suffix based quarter

[darioit]

Hello Everybody,

inside the file I have one row like this "Data end period 30/09/2010"

I need to change the filename suffix in this way

rename file1.txt with inside undefined number line "Data end period 31/03/2010" in file1.10A
rename file2.txt with inside undefined number line "Data end period 30/06/2010" in file1.10B
rename file3.txt with inside undefined number line "Data end period 30/09/2010" in file1.10C
rename file4.txt with inside undefined number line "Data end period 31/12/2010" in file1.10D

where the suffix 10A means Years (YY) and (A,B,C,D) like 1,2,3 or 4 quarter

Regards
Dario