Point 2 Pixels

[G Casey]

Hi, 

I am currently trying to map a lat long point to a map using a
database request and php mapscript.

Something simple at this point like: SELECT name as N,st_abrev as ST ,
AsText(the_geom) as POINT FROM hospitals WHERE name LIKE '%st' LIMIT
60

I am then parsing and re projecting those coordinates into a select
like the one above that would list hospitals. The user can select the
right name and submit it to the application.

It seems to work really well however I am trying to do a large area
and it would be nice to be able to zoom to that location, for that I 
would need to know the pixel location that those points are drawn at
to request the map to "zoomtopoint" Right ? I don't want the user to
click the point I want it to happen as a part of the location
selection.

Could someone tell me if there is an easy way to get this information
from mapscript or proj 4 I am not having the best results trying to
calculate it from the extent and the image dimensions ...although I am
not sure why ?

Thanks 

G Casey