apost or quote in cobol esql

Hi 

compiling cobol + sql program on unix with SQL(DBMAN=ODBC) 

on ORACLE database

give error 

ORA-00904: "C": invalid identifier

if I use 'C' its work, I must change all quote in apost? 

I cannot stay with double quotes in cbl progmram?

EXEC SQL DECLARE CURSOR1 CURSOR FOR
.....
AND (A_COLL = "K" OR A_COLL = "C")   

....
END-EXEC.

thanks 

bye