compare a cell value with values of cells from another workbook

I am new to AS and I wrote this Script in order to check if values from a range in a workbook can be found in the third row of another workbook.

tell application "Microsoft Excel"
	activate
	set data_file to "data sectoriels.xls"
	set indexdatasheet to "DS"
	set file_name to "signal CT.xls"
	set indexsheet to "Index Data"
	open data_file
	activate object sheet indexdatasheet
	open file_name
	activate object sheet indexsheet
	
	set mix_sector_index to range "MIX_SECTOR"
	display dialog (count of cells in mix_sector_index) / 2
	
	repeat with i from 1 to 11 by 2
		set oneCell to cell i of mix_sector_index
		if length of (value of oneCell as text) = 0 then
			exit repeat
		else
			display dialog "Found in " & (get address of oneCell) & " " & (value of oneCell as text)
			set search_sector_code to value of oneCell
			activate object workbook data_file
			activate object sheet indexdatasheet of workbook data_file
			repeat with j from 1 to count of cells in row 3
				display dialog (value of cell i of row 3 of sheet indexdatasheet as text)
				if (value of cell i of row 3 of sheet indexdatasheet) = search_sector_code then
					display dialog "bingo !" & (value of search_sector_code)
					activate workbook file_name
					exit repeat
				end if
			end repeat
		end if
		
	end repeat	
	
end tell

Unfotunately, this script stops on “activate object sheet indexdatasheet of workbook data_file”.

I would be grateful if anyone can help me with this problem.

Pongocito

I don’t see any mistakes but my AppleScript code works with active workbook,
i.e. you are selecting workbook and then code like this

set mysheet to sheet 1 of active workbook

tell mysheet 
    repeat with j from 1 to count of cells in row 3
                display dialog (value of cell i of row 3 of sheet indexdatasheet as text)
                if (value of cell i of row 3 of sheet indexdatasheet) = search_sector_code then
                    display dialog "bingo !" & (value of search_sector_code)
                    activate workbook file_name
                    exit repeat
                end if
            end repeat
end tell

p.s. do you have this?
Excel 2004 AppleScript Reference
http://download.microsoft.com/download/3/A/7/3A70FB4B-0C6A-43E3-AAB7-AC9166B25632/Excel2004AppleScriptRef.pdf