Can you create a balloon that is linked to the BOM on Sheet 01 (Item #) and the location (Sheet 04) of the part drawing if it is on a different sheet? I thought I saw something with a circle with a horizontal line dividing the circle that contained the item number on top and the sheet number on bottom.
I don't know of a way to do that automatically but you can provide the sheet number manually. What we end up doing is to have a custom property in each of our parts called SHEET that we manually enter into each part. Then it populates into the column in the BOM plus will fill in the bottom number of the ballon on the assembly sheet.