Looks like finally I have been assimilated by the copy/paste generation, because the example I wanted to show was actually this one, which truely adds the 8-bits accu to a 16-bit base address.

		add	a,low(base_addr)	;Calculate low order address
		push	acc			;put it on the stack
		clr	a
		addc	a,high(base_addr)	;Calculate high order address
		push	acc			;Both bytes on the stack now
		ret				;Pop them and put them in the PC