Hi Nalmond,
I suppose this is what you want:
Click on a cell, which has to turn in blue and perform eventually other actions on the values of those cells.
Probably you will need a command, to turn this function on and off.
You could proceed like this:
For the On/Off command:
In Excel choose Menu View, Toolbars, Formulas (I am translating from dutch, the real names may be slightly different).
On the toolbar choose the groupform (xyz), and drag a small sqare on your Excelsheet.
Then, from the same toolbar, click the small "choiceround", and drag one in the square.
Take another one and do the same. Position it below the first one.
Now if you click on the buttons, one will turn black and the other white and vice versa.
Click the upper button to make it black. Then rightclick on this button. In the appearing menu, choose the last option (in english something with format...?)
On the last tab, you find Value: Turned off, turned on. Choose Turned on. Click in the textbox "related to cell" and click on the worksheet in cell A1 (or any cell you don't use).
Click OK.
Now if you use your buttons, in cell A1 the values 1 or 2 will appear, depending on the button that is "On".
To use this in SelectionChange:
Choose Tools, Macro, VisualBasic Editor
On the left you find ProjectExplorer (If it isn't there, find the button of that name to make it appear)
Doubleclick on Sheet1 (or whatever sheet you are working on).Above the window on the right, you find "General". In this box, select "Worksheet".
The "frame" for the Private Sub SelectionChange will appear. Add following code:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Set ws1 = Workbooks("TheNameOfYourWorkbook.xls"

.Sheets("Blad1"
r = Target.Row
c = Target.Column
'Note:
'the values of Target.Row and Target.Column are
'automatically known by this sub as soon as you click
'in a cell. This macro starts each time you click in a
'(different) cell.
If ws1.Cells(1, 1).Value = 1 Then
'this is the value of the on'off buttons in A1
ws1.Cells(r, c).Interior.ColorIndex = 5
'colors cell in blue
'if you want to remove color when function blue is
'turned off, you can add
'Else 'if function is “Off”
'ws1.Cells(r, c).Interior.ColorIndex = xlNone
End If
End Sub
Tell me if it works like you wanted.
Greetings,
Rudo (Holland)