Passing a space as an argument to SQL*Plus

[GP]

Consider the following: (extracted from a .bat)

sqlplus toto/titi ^
@%pdl%\islqz033 ^
'1 ' ^
'aaa' ^
' ' ^
'zzz' ^
....
At execution, SQL*Plus stops and ask for the parameter corresponding
to the blank spaces(' ') parameter.

In 8.0 it was working fine, but in 9.2 SQL*Plus does not like it.

I have multiple .bat that use that approach, so a solution with
minimal impact would be appreciated.

Thanks !

NOTE: I've tried both 'set COMPATIBILITY V8' and 'SET
SQLPLUSCOMPATIBILITY 8.0.0' with no luck...