Modifying VB Code:Excell Macro and Visal Basic Programming

[aero777]

Hello All.

I am very new to using Excell Macros, infact just a few hours of use till now.I need a quick help on Macros.
I have a formula in cell B4, which I would normally drag all the way to another cell,B14 .So I created the macro , by pushing the record Macro option. Here it is below.

Sub Macro1()
'
' Macro1 Macro
'

'
    Range("B4").Select
    Selection.AutoFill Destination:=Range("B4:B14"), Type:=xlFillDefault
    Range("B4:B14").Select
End Sub

Question : How can I change this script so that the Macro is executed from cell B4 to BX , the number X , would be decided by a value in cell B2. If the value is 10 ,
then the macro should execute from "Cell:B4" till "Cell:Address of B4 + 10"