postgis and query

[Alberto Cavalli]

Hi dear,
I'm working with postgresql 8.0 beta1, postgis 0.9 and mapserver 4.0 on win
2000.
I putted all my shape in my db and I need to make a query below in my web
page:

select h887_p.num_foglio, h887_p.num_part, h887_p.area as area_particella,
round(
(area2d(intersection(geometryn(h887_p.the_geom,1),geometryn(v_pub.the_geom,1
)))/area2d(h887_p.the_geom)*100)::numeric ,0) as percentuale from h887_p
,v_pub
where (h887_p.the_geom && v_pub.the_geom);

My problem is thath I don't know how can I make this query in mapserver for
a specific point, I think thath I need phpmapscript and querybypoint.
Can someone explain to me the right way to do this or send an example of
this?
thanks in advance
Alberto