Example 1:

Enter B-B1 as formula in column E. Ctrl+Drag the F(x) cell corner to the right will fill C-C1, D-D1

Drag without holding Ctrl key, it will fill with B-B2, B-B3 (only incrementing number at the end)

Example 2:

In Book3, set column B’s F(x) as [book1]1!B+[book2]1!B, then Ctrl+Drag the tiny bottom-right corner of the F(x) cell to the right, it will column C, D, … 's formula as [book1]1!C+[book2]1!C, [book1]1!D+[book2]1!D, ….