how to parse this specific text

i am stucked in this crictical problem and i don't know how to cater this. I sometimes receive this String ⒗⒕►☻☺ and sometimes  these are non US-ASCII characters. These ⒗⒕►☻☺ characters are replaced by ? and  is represented as it is. I sometime receive this character  too. These characters are in ANSI list but i want to receive only US-ASCII. Please help me out that how to identify these characters in the string.

[463 byte] By [GameOvera] at [2007-11-26 17:28:16]
# 1
They are undoubtedly hex. Download a hex editor and view the values to see if they make sense. If you simply want to strip out the alphanumeric characters, write a simple RegEx expression.- Saish
Saisha at 2007-7-8 23:56:12 > top of Java-index,Core,Core APIs...