Hi Nayak ,
This is something you can figure out this way.
1. The moment you add the words diff to the output , what is going to result is a text string.
Hence formatting the cell will not give you the result you are looking for ; the only way to get the desired output format will be to use the TEXT function with the desired output format string.
If your system locale is India , then when you format a cell by clicking on the comma button , the format which results is an Accounting format , with the following format string :
_ * #,##0.00_ ;_ * -#,##0.00_ ;_ * "-"??_ ;_ @_
It is a simple matter to eliminate the decimal places , to get :
_ * #,##0_ ;_ * -#,##0_ ;_ * "-"??_ ;_ @_
Use this as the output format string with the TEXT function , as follows :
="diff " & TEXT(N2-M2,"_ * #,##0_ ;_ * -#,##0_ ;_ * ""-""??_ ;_ @_ ")
Note that the two double quotes around the hyphen are required because the normal double quote is around the format string itself , and so any quote symbol within has to be used twice for it to be recognized as a literal double quote.
Narayan