Display amount in ALV with front negative sign

# in SE37 create Z conversion Exit->

"CONVERSION_EXT_ZSIGN_OUTPUT"

function conversion_exit_zsign_output.
*"----------------------------------------------------------------------
*"*"Local Interface:
*" IMPORTING
*" REFERENCE(INPUT)
*" EXPORTING
*" REFERENCE(OUTPUT)
*"----------------------------------------------------------------------

data: lv_value type char30.
lv_value = input.

* Fm to display sign at front it returns value in char
call function 'CLOI_PUT_SIGN_IN_FRONT'
changing
value = lv_value
.

output = lv_value.

endfunction.

In Fieldcat of ALV use:

gs_lvc_s_fcat-edit_mask = '==ZSIGN'.