ARM startup file with scatter file heap/stack placement

Hi,

I am using:
ARM Compiler/Assembler/Linker on Cortex-M0.

Given the following template for startup.s:
www.keil.com/.../startup_s_pg.html

Stack_Size      EQU     0x00000400

                AREA    STACK, NOINIT, READWRITE, ALIGN=3
Stack_Mem       SPACE   Stack_Size
__initial_sp

I want to define my memory regions(including stack) in scatter file. However, I want to use the start address of my Stack in my code.

My scatter file is as follows:

LOAD START_ADDRESS LR_SIZE
{
    RAM RAM_START_ADDRESS
    {
        *(INTERRUPTS, +First)
      .ANY (+RO)
      .ANY (+RW,+ZI)
    }
    STACK_SPACE END_STACK_ADDR UNINIT STACK_SIZE
    {
        *(STACK)
    }

}

I want __initial_sp to point to the END_STACK_ADDR + STACK_SIZE in the startup file and I want to export __initial_sp so that my application can use it.

I have attempted to use Image$$STACK_SPACE$$ZI$$Limit and Image$$STACK_SPACE$$ZI$$Base in my startup.s file but EQU and SPACE does not take these values (not constant).

Stack_Size      EQU    |Image$$STACK_SPACE$$ZI$$Limit|

How can I reserve SPACE in my startup file with a value of stack size defined in scatter file so that my __initial_sp points to the right location?

if that's not possible, how can I export a variable in my startup.s file that has a name __initial_sp and value of |Image$$STACK_SPACE$$ZI$$Limit| ?