Automatically copy text data from one cell, into another cell, by entering the row number

Hi guys.
I've got a sheet drawn up for our Work Lotto Bonus ball game
Its simple enough layout, with the Rows representing the 49 numbers in the lotto, and the columns representing the Week/draw dates.
I then enter the names of people taking part, in their chosen week/number cell.
The first 4 rows, before the numbering starts, i have Date, Winning number, winners name, and the winning prize amount.
If there is no winner, the pot rolls over into the following week.
I can manually enter all this info, but what i want to do is type in the winning number, and then have it automatically fill in the name of the winner.

For example:
I type in number 30 in row 2
In row 30, is Bob (lucky Chap)
The sheet automatically takes bobs name, and copies it into row 3, under the winning number.
There is a winner, The prize amount (in row 4) is won, so the following weeks pot stays the same.

If there is no winner, no name appears in row 3, and the prize pot in row 4, then gets added to the pot already in Row 4 of the next column.

I'm very new to excel and have next to no experience in it so any help would be hugely appreciated.
I have attached a demo Xls of the spreadsheet i am trying to complete.
Thanks in advance