How to skip dates and alpha numeric values from a column by using a formula in ms excel?

Friends I have a mixture of dates, alpha-numeric values and numeric values in column a. I want a formula in column b which can insert the numeric values from column a into column b skipping all dates and alpha-numeric values. For better understanding I am attaching a screenshot of excel sheet. I request you to provide me a formula for this purpose instead of vba coding. Thanks a lot friends. Screenshot- http://imgur.com/ngpjln4