Hi experts

I am slowly working through my sheet problem. The stumbling block I am now on is this:

I would like to lookup and display entries in a row of data using the date. However, the first column with the date in it also stores the time next to it, like this:

dd/mm/yyyy hh:mm

I can use a vlookup as follows: =VLOOKUP(DATEVALUE("05/04/2015"),C12:K110,4,FALSE) and when the entry was exactly at midnight, 12:00:00am (very rare but a few samples were done bang on midnight) will give me the result.

I am wondering there is a way for the VLOOKUP to disregard the time, and only look for relevant dates. As I have a lot of entries each with totally random times.
Thankyou for any help, I have been looking all over this site like crazy the last couple of days, its fantastic!