Dynamic array in Index

Hello,

Here is my formula

"=INDEX(Report!R3C4:Report!R933C4,MATCH(Compare!RC[-1],Report!R3C2:R933C2,0))"

This works fine. However i want to make it dynamic. Number of rows in the sheet report will vary. So i want to make it dynamic array. I can use the following method to find the number of rows

Lastrow = Cells.Find("*", [A1], , , xlByRows, xlPrevious).Row

How Can i make the index formula dynamic with this variable?