If each field in a tabble is the same size, usually you multiply the index and add the address (constant) of the first entry. like

;index is in a

	mov	b,#7		;Multiply index by 7
	mul	a,b
	add	a,#low(asc32)	;low byte offset
	mov	dpl,a
	mov	a,b
	adc	a,#high(asc32)	;high byte offset
	mov	dph,a

;Now dptr points to the appropriate field.