Filter special characters

Hi Experts,

I have a requirement wherein I am required to check a field for special characters and allow only those set of characters that are supplied by the client into the field. These are:

' ¢[]°

ᦀ

{}|#^-×´º

Æ¡±¯[

b]²¿Æ¶«»Ð³° '

Out of these the ones marked in bold are not visible on the ABAP editor but are displayed either as '?' or are replaced by alphabets; ie ß is displayed as B, Ç is displayed as C etc.

Would these characters be interpreted as their original values or would they be interpreted as they are displayed during processing? Because if they are interpreted as they are displayed, then some required chars would be filtered out by the program.

Regards,

Ram