Please help me with the macro code

Hello,
Please provide me with the macro code for the following problem ,as I am new to excel macro

i have four columns Batch No,Title,Query,Asset .The batch no,title,Query will remain for a given set of rows.Asset will vary .Sometimes the value of asset might be duplicated. I need to delete the duplicates and put the number of duplicate entries in another column.For unique entries it should be one

before the macro is executed
Batch No Title Query Asset No of listings
1 Apple app apple
1 Apple app apple
1 Apple app apple
1 Apple app apples
1 Apple app application
1 Apple app application
1 Apple app application
1 Apple app applied

after the macro is executed

Batch No Title Query Asset No of listings
1 Apple app apple 3
1 Apple app apples 1
1 Apple app application 3
1 Apple app applied 1

thanks in advance