First install the follow macros in a standard module:
Public RunWhen As Double
Public Const cRunIntervalSeconds = 1
Public Const cRunWhat = "The_Sub"
Sub StartTimer()
RunWhen = Now + TimeSerial(0, 0, cRunIntervalSeconds)
Application.OnTime earliesttime:=RunWhen, procedure:=cRunWhat, _
schedule:=True
End Sub
Sub The_Sub()
'
Range("A1").Value = Range("A1").Value + 1
'
StartTimer
End Sub
Sub StopTimer()
On Error Resume Next
Application.OnTime earliesttime:=RunWhen, _
procedure:=cRunWhat, schedule:=False
End Sub
Then put an initial value in A1.
Then run StartTimer.
Macros are very easy to install and use:
1. ALT-F11 brings up the VBE window
2. ALT-I
ALT-M opens a fresh module
3. paste the stuff in and close the VBE window
If you save the workbook, the macro will be saved with it.
To remove the macro:
1. bring up the VBE window as above
2. clear the code out
3. close the VBE window
To use the macro from Excel:
1. ALT-F8
2. Select the macro
3. Touch RUN
To learn more about macros in general, see:
http://www.mvps.org/dmcritchie/excel/getstarted.htm