HiRDB hasn't equivalents for CHARTOROWID function. SQLWays leaves it as is and adds message /* SQLWays: Could not convert 'CHARTOROWID' */.

Oracle:

n := CHARTOROWID(a); 

HiRDB:

SET n = CHARTOROWID(a);
/* SQLWays: Could not convert 'CHARTOROWID' */ 

References in Wiki