Macro to expand unique rows into duplicated rows a certain number of times for each row

Hello! I'm new to VBA, although I know some Java. I'm looking for a macro that takes a sheet like

A B C 4
D E F 2
G H I 5

and creates a new one like:

A B C
A B C
A B C
A B C
D E F
D E F
G H I
G H I
G H I
G H I
G H I


In the first sheet, the last column would be separated from the rest by a blank column and the rows to be duplicated could be of one column or more.

Thanks to anyone who can help!