That removes special characters from flat file

Basically the script searches through a flat file if there are any special characters within the file it should remove them and replace with a space . The are occasions where email address will have @ symbol those should remain. we should be able to add other special characters which are allowed within the file .
please advise

It isn't clear what you are asking - what script? How is that related to SQL Server?

is this related to this one?