test each cell of an Excel range

I am new to AppleScript and i want to develop some macros for Excel.
I have a range name, and only its name. I do not know its position on the sheet. I do not know the number of rows and columns within the range. I want to test if there is something in each cells. if there is something, i will copy the value somewhere else and exit when i reach the first void cell.

Someone can help me with this ?

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Operating System: Mac OS X (10.5)

Perhaps something like this

tell application "Microsoft Excel"
	set myRange to range "myNamedRange" of active sheet
	repeat with i from 1 to count of cells in myRange
		set oneCell to cell i of myRange
		if value of oneCell = "target" then
			display dialog "Found in " & (get address of oneCell)
			if length of (value of oneCell as text) = 0 then
				exit repeat
			end if
		end if
	end repeat
end tell

many thanks

Many thanks,

This script works quite well. How can I only refer to the cells of the first column of the range ?