Associate two columns with conditionals

Dear Reader
Let me show you my situation:

Date Number Date Replacement for x
1/2/13 x 1/2/13 3.1
1/2/13 x 2/2/13 3
2/2/13 x 3/2/13 2.8
3/2/13 x 4/2/14 5
3/2/13 x
4/2/13 x
4/2/13 x


So what I want to do is: to replace "X" with the number under the colum titled "Replacement for x", but only if the date for x and the date for the number are the same. If the date for x is repeated 4 times, the number is placed 4 times consecutively. This is what I want my result to be:

Date Number Date Replacement for x
1/2/13 3.1 1/2/13 3.1
1/2/13 3.1 2/2/13 3
2/2/13 3 3/2/13 2.8
3/2/13 2.8 4/2/14 5
3/2/13 2.8
4/2/13 5
4/2/13 5
4/2/13 5

And I need to do this function so I can drag it down and this process is repeated in as many cells as I need.

PLEASE HELP ME DO IT IF YOU KNOW HOW TO, I AM DOING THIS FOR AN IMPORTANT PROJECT AND I AM TRULY DESPERATE!!!

Kind Regards,
Diego O.

I think you need a simple vlookup formula... check out the attachment... (you have to set up your lookup table first)

simple vlookup.xls

Well thank you so much djapigo! I will try your solution right away and let you know how it worked out for me!

It worked exactly how I needed it! Thank you so much!