I understand there is not concatenate in the example below - its because I havent figured out how to make it work yet.

I have a row with the names of tabs in a file
I want to create a sumif function that will automatically pick up the name of the file.

example
3156 2689 3032 3094 - this is just 4 of 350 columns

my current equation which i have to manually change the 3156 to 2689 for the next column - all other parts of the equation stay the same.

=SUMIF('3156'!$B:$B,Summary!$B3,'3156'!$P:$P)

Any help would be awesome - i find myself in this situation a lot and haven't found a answer to this via google search yet.

thanks