Hi Satish ,
You do not need to bother even if this macro does not show up in the Macros menu.
What you do need to do is :
Copy this macro in whichever sheet section that this applies to e.g. if you want that modified rows in Sheet4 need to be copied into a new sheet ( by the way , this new sheet will always be Sheet2 , since this is hard-coded into the macro ) , then copy this code in the Sheet4 section of your VBA Project.
Since this is an event macro , it will be triggered automatically whenever any cell in the range Q2:AA400 on tab Sheet4 is changed by the user ( remember that changes in any formula within this range due to a change in any other cell outside this range will not trigger this event ).
Also , please remember , the entire row is copied to a new row in the new sheet based on an assumption that column A will contain some data ; if column A does not contain data , then the new modified row will always be copied to row 2 in the new sheet , thus overwriting the earlier written data.
Narayan