I am in the throes of setting up an Org mode spreadsheet for an
invoicing/status/planning tool and came across this fabulous thread: *[O]
org table calc and lisp for hh:mm
timetable<http://lists.gnu.org/archive/html/emacs-orgmode/2011-03/msg00972.html>
 *at http://lists.gnu.org/archive/html/emacs-orgmode/2011-03/msg00972.htmlwhich
provided me much of what I need.  So thanks to all involved for that
excellent piece of work.

The one problem I am having trouble grasping is in how to use Emacs Lisp to
generate a range of values automagically.  I have no trouble with a single
cell using Lisp and passing in a rectangular region to process or in
setting up a region using the Org table/spreadsheet/calc support described
in the various Google accessible documentation.

What I am trying to do at a high level is setup a table with rows of
actions spanning a start and stop time.  Each action row has a bill-to
category column.  In the table, as part of a Lisp based formula, I want to
process these action rows and build a list of "bill-to : total time"
summary values and then place these summaries in a range in the table, so a
fragment of the table might look like:

... | Client1 | Client2 | Commute | ...
... |  12.50  |  22.00  |  10.5        | ...

where the numbers (hours)  have been summed by filtering the task rows by
clients.  Hope that's clear.

So there are essentially two issues for me:  the first is understanding how
to associate a range destination for a Lisp based formula result, which I
think can be done, I just do not understand how to do it yet, and second,
probably an enhancement request, is to figure out how to pass a list of
cell addresses to a List form (along with other data) and have the form
compute and store values to those cells.  The latter would a sort of holy
grail, at least for me.

Thanks,

-pmr