The default delimiter characters used in macro text strings and macro names are the pound ("#"), percent ("%"), and the exclamation point ("!"). These characters can be changed with the $PREPROCESSOR directive.
$PREPROCESSOR parameter=new-character [, parameter=new-character, ...]
parameter specifies which character to modify; and
new-character specifies the new character.
The following parameters can be modified.
KEYCHAR - defines the initial character of a macro name. The default character is "%".
DELIMITER - defines the character that delimits the end of macro text strings and the actual parameters used with macro calls. The default character is "#".
PARMCHAR - defines the initial character of each formal parameter within macro text string. The default character is "!".