How to put data from a cell into an if state?

Hello Peeps, been using this site a lot and i have come quite far now, but this thing i cant figure out: I am making a datafile in excel 2003? which should change cells into red when exceeding certain limits: =IF('raw datafile'!B200<0;"0";"xxxx") but in the xxxx part i tried to refer to data from 'raw datafile'!b200, what i cant get fixed. In other words: I have an if statement in which a certain number should be displayed into a cell, unless its below zero, or negative, because then there should be only "0". if i place the 'raw datafile'!b200 between instead of the xxxx it just sais all that -.- I tried some stuff but it doesnt work and i am getting a bit frustrated since google aint working like i want it either :P I hope you can help me ! Gr D.