Checking multiple cells for text string using FORMULATEXT

[ormy28]

Hi
I am working on a dashboard which pulls data from external excel files across multiple different columns. For the sake of this example, the columns which contain this external data are C, D and E in row 7.

I want to add a column at the end of the dashboard which checks the formulas in columns C, D and E to ensure that all columns are pulling data from the same external file. Columns C, D and E are pulling the data from the external files using a VLOOKUP, therefore I believe I will need to use the FORMULATEXT function. At the moment, I have done this using a combination of IF, AND, FORMULATEXT and SEARCH functions. For example.

=IF(AND(SEARCH(A7,FORMULATEXT(C7))>0,SEARCH(A7,FORMULATEXT(D7))>0,SEARCH(A7,FORMULATEXT(E7))>0,"CORRECT","INCORRECT")

The filename is stored in cell A7.

Whilst this will highlight instances where the incorrect file is included in any of the three columns, it isn't ideal. This is due to the fact that this dashboard is likely to grow massively over the next few months, potentially to 40+ columns! This will result in a very long formula.

Is there a more efficient way I can check the same file is used in multiple columns?

I am using Excel 2013.

Thanks