How to make If statement comparing dates and value from another cell?

I have made an excel file in wich in Sheet2 there is a list of dates (that list is static) then on Sheet1 I have a field (D column starting in D11) where the user inputs any date, in column K there is an static number and another field where the user inputs a number (Column L). What I want to do is validate that the date in Sheet1 in Dn is in the list of dates in Sheet2 and also (AND validation) the value in Ln cell is below Kn cell value. I do not know how to start coding, any help would be great. If that validation is right, the row (Bn to Mn) would be green otherwise would be red