How to count back 4 weeks, skipping blank cells

[Lars53]

I am using excel to analyze stock changes. Yahoo spits out a column with dates and another with closing prices but occasionally inserts a row showing a dividend, something like this:
Date Closing price
12/30/13 120
12/23/13 118
12/16/13 119
12/9/13 117
12/2/13 115
11/25/13 116
11/22/13 dividend 0.23
11/18/25 116
11/11/13 115

In the spreadsheet, column A is date and Column E is closing price, such that the cell in column E where the dividend is listed is blank.

The problem- as I update data each week, the dividend row moves. How can I consistently figure price changes for 4 weeks and 13 weeks without getting messed up by the dividend row? Is there to auto delete the row or make the formula count down 4 cells in the price column, while skipping any cells without data?

I am attaching a sample worksheet
Thanks