Okay, I couldn't help myself. This is very possible.
In Excel 2007, click on the Developer Tab and then click on the Macros icon (on the left, in the Code section).
A Macro dialog box will open. In the Macro name: field, type in some name for your macro and click the Create button.
A Visual Basic window will open, with a blank Module window inside.
Cut and paste the following text (everything between, but not including, the **** rows) into the Module window
*******
Sub ColourHeader()
' Sets Row and Column Header to Red if they contain a cell with letter "S"
' Note, "S" in spread sheet must be a capital!!
Dim ColumnRange As Range, RowRange As Range, OneCell As Range
Dim Col As Integer, Rw As Integer
Dim MaxCol As Integer, MaxRow As Integer
MaxCol = 50
MaxRow = 50
'Clear all Column and Row Headers
Range(Cells(1, 2), Cells(1, MaxCol)).Interior.ColorIndex = xlNone
Range(Cells(2, 1), Cells(MaxRow, 1)).Interior.ColorIndex = xlNone
'Go through each column
For Col = 2 To MaxCol
Set ColumnRange = Range(Cells(2, Col), Cells(MaxCol, Col))
For Each OneCell In ColumnRange
If OneCell.Value = "S" Then
Cells(1, Col).Interior.ColorIndex = 3
End If
Next OneCell
Next Col
'Go through each row
For Rw = 2 To MaxRow
Set RowRange = Range(Cells(Rw, 2), Cells(Rw, MaxRow))
For Each OneCell In RowRange
If OneCell.Value = "S" Then
Cells(Rw, 1).Interior.ColorIndex = 3
End If
Next OneCell
Next Rw
End Sub
********
Now click Run from the Visual Basic (VB) window top menu bar, and select Run Sub/User Forum (or use the green arrow run icon if you can find it).
This should colour the row and column headers for any cell that has a capital "S" in it.
You can now close the VB window.
You can also set up a short-cut key, so that every time you make changes to the spread sheet, you just need to press your short-cut key to have the colouring update.
To do this, click on the Macro icon and in the Macro dialog box, select your macro and click Options.
In the Macro Options dialog box that opens, set your shortcut key to whatever you want and click OK.
From now on, you can use your shortcut key to update your colour coding (or run through the Macro dialog, your choice).
Oh, and I just checked. You can save this spreadsheet with the Macro in 2003 format.
Good luck and let me know how it goes....