I'm wondering if anyone could help me out with some basic "astrological addition and subtraction". >

I just finished reading E. W. Neville's book PLANETS IN SYNASTRY. He talks about using a solar chart to determine "how we are seen by others" (in much more detail than just information provided by the ascendant,etc.).
He says:
"The formula is simple enough and many will recognize it as the same one used to calculate the various "Parts" favored by Hindu astrologers. The array of planets remains constant,the aspects between them do not change,but planets do assume new sign and house positions based on the angular relationship between the Ascendant and Sun in the natal chart.
The Ascendant and Sun exchange their natal roles so that the Sun provides the cusp of the 1st House from which all the remainder of the house cusps can be derived. Then the remaining planetary positions are calculated as follows:
ASC + Moon minus Sun = Solar Moon position
ASC + Mercury minus Sun = Solar Mercury position
(and so forth with the same" ASC + planet minus Sun = Solar planet" formula through all the planets)
My questions for anyone willing to help are : have you ever used this chart and do you think it is valid? If so,how do you derive the remainder of the cusps? And what exactly does "ASC + Moon minus Sun" mean?
I find this idea fascinating because as Neville says "This chart presents an image of what we project to others as our basic persona and goes a long way toward explaining why others so often misread us, misunderstand our objectives and motives,and simply believe we are something quite different than we know,deep down inside,that we really are." Thanks!--Emmy