How would you create a conditional %define in asm

I'm tring to create a conditional address statement in my start167.a66. The goal is to be able to use the same start up file with different uv2 targets. one target would be stand-alone and the other target needs to coexist with a bootloader ROM.
(The programming tools I have available can only program CS0 )

I tried to create a block using the if/else statement but found out the hard way that the last/latest %Define statement will over ride any previous ones.

; BUSCON2/ADDRSEL2
; --- Set BUSCON2 = 1 to initialize the BUSCON2/ADDRSEL2 registers
$SET (BUSCON2 = 1) ; Uv2/Dave

;$IF (I_USE_CS0 = 1)     ; pick you chip

%DEFINE(ADDRESS2) (80000H) ;  0x80000 clears the 1'st ROM by 2 times (8*64K)->2x256
%DEFINE(RANGE2) (256K)      ; (this setsup a mask for start address as well as size

$ELSE  ;][ App Programs are to run out of the second ROM and expect intr table @0
%DEFINE(ADDRESS2) (00000H) ; MUST BE SET TO 0! or no intrupts will work
%DEFINE(RANGE2) (256K)     ; only limited by
$ENDIF ; ] of changed chip config

the only other approach I can think of his two break these lines out into other files and then let the IF/else pick one of them. Does anyone have a cleaner approach?