To write a formula that will sum "the next 3" cells each time it's copied, you can use the OFFSET function. In the example shown, the formula in O5 is:
=SUM(OFFSET($B5,0,(COLUMN()-COLUMN($O$5))*3, 1,3))
Note: the...

To lookup a value by matching across multiple columns, you can use an array formula based on the MMULT, TRANSPOSE, COLUMN, and INDEX. In the example shown, the formula in H4 is:
{=INDEX(groups,MATCH(1,MMULT(--(names=...

To generate a fixed value every N columns (for example, a fixed expense every 3 months, a fixed payment every 6 months, etc.) you can use a formula based on the MOD function.
In the example shown, generate a value of...

To get the max of every nth column, you can use an array formula based on the MAX, MOD, and COLUMN functions. In the example shown, the formula in M5 is:
=MAX(IF(MOD(COLUMN(B5:K5)-COLUMN(B5)+1,L5)=0,B5:K5))
Note:...

To get the full address of a named range with an Excel formula, you can use the ADDRESS function together with the ROW and COLUMN functions. In the example shown, the formula in G5 is:
=ADDRESS(ROW(data),COLUMN(data),...

To count rows that contain specific values, you can use an array formula based on the MMULT, TRANSPOSE, COLUMN, and SUM functions. In the example shown, the formula in G5 is:
{=SUM(--(MMULT(--(data=90),TRANSPOSE(...

To copy values or generate references with a pattern like every 3rd column, every 5th column, etc. you can use a formula based on the the OFFSET and COLUMN functions. In the example shown, the formula in C8 is:
=...

To get the address of the first cell in a named range, you can use the ADDRESS function together with ROW and COLUMN functions.
In the example shown, the formula in G6 is:
=ADDRESS(ROW(data)+ROWS(data)-1,COLUMN(data...

To get the address of the first cell in a named range, you can use the ADDRESS function together with the ROW and COLUMN functions.
In the example shown, the formula in G5 is:
=ADDRESS(ROW(data),COLUMN(data))
How...

To convert a column letter to an regular number (e.g. 1, 10, 26, etc.) you can use a formula based on the INDIRECT and COLUMN functions.
In the example shown, the formula in C5 is:
=COLUMN(INDIRECT(B5&"1...

If you need to dynamically increment a calculation, so that a value automatically increments each time the formula is copied to a new row or column, you can use the ROW() or COLUMN() functions in your formula.
In the...

To count with repeating numbers (for example: 1111,2222,3333,4444, etc.) you can use a formula based on the ROUNDUP function, with help from either ROW or COLUMN.
In the example shown, the formula in C4 is:
=ROUNDUP...

You can get the last column in a range with a formula based on the COLUMN function.
In the example shown, the formula in cell F5 is:
=MIN(COLUMN(data))+COLUMNS(data)-1
where data is a named range for B5:D10
How...

To sum the last n columns in a table of data (i.e. last 3 columns, last 4 columns, etc.) you can use a formula based on the INDEX function. In the example shown, the formula in K5:
=SUM(INDEX(data,0,COLUMNS(data)-(K4-...

To sum every nth column, you can use a formula based on the SUMPRODUCT, MOD, and COLUMN functions.
In the example shown, the formula in L5 is:
=SUMPRODUCT(--(MOD(COLUMN(B5:J5)-COLUMN(B5)+1,K5)=0),B5:J5)
How this...