go to .htm page
find which is source of button
it can be
get_toolbar_buttons(),get_buttons() or a attribute in controller class
then redefine the source , call the super class method and get the table ,loop it and disable the copy button
for eg:
method IF_BSP_WD_DYN_BTN_CONTROL~GET_BUTTONS.
FIELD-SYMBOLS <fs_button> TYPE CRMT_THTMLB_BUTTON.
CALL METHOD SUPER->IF_BSP_WD_DYN_BTN_CONTROL~GET_BUTTONS
RECEIVING
RT_RESULT = RT_RESULT.
**********************************************************************************************
LOOP at RT_RESULTASSIGNING <fs_button>.
if <fs_button>-ID = 'COPY'. "plese debug and find button id which is to be disabled
<fs_button>-ENABLED = abap_false.
endif.
***************************************************************else**************
DELETE RT_RESULTWHERE id = 'COPY'.
*****************************************************************
ENDLOOP.
endmethod.