Don't worry. Thanks to you in any case for your time.
I try to explain better.
Like the number 1 can be represented in various way:
"1" (String)
1 (Int)
0x01 (Hex)
Also what I (unfortunately) have is a Byte Array but for ugly reasons is represented in String.
So i need
"0x33303a43363a46373a30303a39353a3641" (String) ------ become ----> Array as Byte (33, 30, 3a, 43, 36, 3a, 46, 37, 3a, 30, 30, 3a, 39, 35, 3a, 36, 41)
In this manner i can take them and put inside ByteToString(bytes, 0, length, "UTF8") and finally get ---> "30:C6:F7:00:95:6A" (String)