Hello, I am having big problems with a microsoft excel project and am hoping somebody can help me here.

Basically I have a table of data that at certain points in each year (the columns are date headed) needs to have a figure to take away (for example at christmas when nobody works) This also occurs on the second sunday of every month, I have created a table in a seperate worksheet which shows all of the second sundays of every month throughout the year. And years to come. What i need is a lookup function that recognises the date of the column, goes to the worksheet and then checks to see if its weekcommencing date is on the sheet, if it is true then 12.5 needs to be placed in the relative cell in the column, if not then the cell needs to remain 0.

I have an average understanding of programming in SQL but do not know much about excel, I need a function similar to an IF statement I think.........?

Any help much appreciated

Peace