Many thanks to both Barry and HD. I also took advantage of the posted examples from http://macosxautomation.com/applescript/iwork/numbers/table-edit.htmlto give this:
set the_mon to month of (current date) as integer as string
if (count characters in the_mon) = 1 then set the_mon to "0" & the_mon
set the_day to day of (current date) as string
if (count characters in the_day) = 1 then set the_day to "0" & the_day
set the_date to the_day & "/" & the_mon & "/" & text 3 thru 4 of (year of (current date) as string)
tell application "Numbers"
activate
try
if not (exists document 1) then error number 1000
tell document 1
try
tell active sheet
set the selectedTable to ¬
(the first table whose class of selection range is range)
end tell
on error
error number 1001
end try
tell selectedTable
set format of cell 1 of selection range to text
set value of cell 1 of selection range to the_date
end tell
end tell
on error errorMessagenumbererrorNumber
if errorNumber is 1000 then
set alertString to "MISSING RESOURCE"
set errorMessage to "Please create or open a document before running this script."
else if errorNumber is 1001 then
set alertString to "SELECTION ERROR"
set errorMessage to "Please select a table before running this script."
else
set alertString to "EXECUTION ERROR"
end if
display alertalertStringmessageerrorMessagebuttons {"Cancel"}
error number -128
end try
end tell