I need to know how to copy numerous columns so I can paste them at the end,
(basically just expanding the worksheet to include more data) but I want the
formula in each cell for each subsequent column (in one row) to just go up by
1 each time.

For example if a cell's formula is C1+1, then the next cell is C1+2, then
the next cell is C1+3... How do I get that to continue when I paste in the
whole columns containing the C1+1, the C1+2, and the C1+3 cells in a row?...
+4, +5, and so on?

It's gotta be so simple that I just can't figure it out.