You can use Conditional Formatting for this:

If you have Excel 2003 or older:
Select your range of cells to apply the "sight lines" to
From the Format Menu, choose "Conditional Formatting"
Change "Cell Value Is" to "Formula Is"
Enter the formula: =MOD(ROW(),3)=0
Click the Format Button
Choose your format (fill color and/or borders)
Click OK

If you have Excel 2007:
Go to the "Styles" section of the Home Tab
Click on "Conditional Formatting"
Select "New Rule"
Select "Use a formula to determine which cells to format"
Enter the formula: =MOD(ROW(),3)=0
Click the Format Button
Choose your format
Click OK

Note: You can adjust the numbers 3 and 0 in the formula to change how many
rows are skipped, and which row the formatting starts on.

HTH,
Elkar
"bart972" wrote:

I would like to automatically add a "sight line" across my spreadsheet, about
every 3rd or 4th row. This could be a line (border) or maybe a shaded row.
Is there an easy way to do this?
--
bart972