How to replace values less than zero in a cell array with NaN?

I have a huge cell array and there is a column with a lot of negative values. I want to clean up and replace all those values with NaN. Would appreciate any help. Thanks.

Answer 1

[Azzi Abdelmalek]

% for all columns

B=cell2mat(A)
B(B<0)=nan
A=num2cell(B)

%if column 2 for e.g

B=cell2mat(A)
B(B(:,2)<0,2)=nan
A=num2cell(B)

[Iknoor Singh]

Thanks Azzi, that helped a lot.