hi,

	add	a,low(base_addr)	;Calculate low order address
	push	acc			;put it on the stack
	mov	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

The idea is right but just do not forget '#' next time:

	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

...and do correct calculations as well.

Regards,
Oleg