Convert excel column to date

Question

hi there,

I'm having problem converting a column to date type in excel. I have an excel that user will upload. I will create a new clean excel file after i deleted the columns and rows that i don't need and save it.The new excel file contains 5 columns namely Date in, Date out, time in, time out, name. Before uploading to database, I have to check the month and year against month and year user select in combobox in the Date in and Date out column. if its correct then i will upload the selected data to database. What I'm having problem here is that the data in Date in and Date out is like this: e.g 24.08.2009. Can the program knows that this is a date format? and my another question is how do i extract the month and year to compare in two different separate combobox?

Any help will be appreciated. I'm really new to programming. Thanks