Using formula to change letter in 1 column based on info in multiple columns

So..I am going to try and explain this the best I can..

I am using the formula below to change the text in column D13 to either NC or P- depending on the info in E13 (will have info and either NC or P). I will be adding columns each week and would like to have it look across all columns and change the text in column D depending on what it finds...I have tried adding AND but that I either get an error or it doesn't change the text in column D???

=IF(ISNUMBER(SEARCH("NC",E13)), "NC", "P")

Any help would be great!!!

Thanks!