Keeping column formulas in a table header - vba

Question

Is it possible to have the formulas that I need applied on columns be saved or applied to a column header or some kind of metadata so that as and when I add new rows to my Excel table the Formulas get applied to the columns?
Scenarion:
I am creating a template Table, which will have no rows at first.
On a separate sheet (or same sheet for that matter) once the user selects the number of rows to be generated in the table, I dynamically add rows to the table using VBA.
The idea is I may not have any rows in the table at beginning OR user may have deleted rows manually.
When I programmatically add new rows, I want the Formulas applied on the cells as well. Most of the formulas I am using are either of the three types:
Structured table reference, Excel functions like SUM, AVERAGE etc and custom function names.
Updated:
Here is what I have tried:
1> tried applying the formula to the header itself.
Result: The header it self changes with #REF! error. I think the behavior is correct. So it's a no-go option.
2> Tried creating one row and apply the formula to the row. That works, but the problem is, I do not want a dummy row to begin with.
3> Using VBA code to add row to the table using
ActiveWorkbook.Worksheets("Sheet3").ListObjects("Table2").ListRows.Add AlwaysInsert:=True
inside a for loop.
The new rows retain the visual style sheets, but does not seem to retain the formulas. Just blank cells.

Answer 1

Could the fomrmulas be in header cell commnets?
And then with VBA add the formula for the current row:
Sub test()
Dim headerCells As Range
Set headerCells = Range("B2:E2")
OnNewRow 3, headerCells
End Sub
Sub OnNewRow(newRow As Integer, headerCells As Range)
Dim headerCell As Range, targetCell As Range, formulaFromComment As String
For Each headerCell In headerCells
formulaFromComment = GetFormulaFromComment(headerCell)
If (formulaFromComment = "") Then _
GoTo NextHeaderCell
Set targetCell = Intersect(headerCells.Worksheet.Rows(newRow), _
headerCell.EntireColumn)
AddFormula newRow, targetCell, formulaFromComment
NextHeaderCell:
Next
End Sub
Sub AddFormula( _
newRow As Integer, _
targetCell As Range, _
formula As String)
formula = Replace(formula, "{ROW}", newRow)
targetCell.formula = formula
End Sub
Function GetFormulaFromComment(headerCells As Range) As String
' TODO
GetFormulaFromComment = "=SUM($C${ROW}:$E${ROW})"
End Function

Answer 2

Just use tables.
If you highlight cells and choose Insert Table from the ribbon, it doesn't just give you formatting and filters. It also, if you build them the right way, stores column formulas once per column instead of once per cell. Also, the formulas are more readable!
For formulas, you can't use cell addresses if you want it to be a single column formula unless they are absolute. (E.g. $A$1, not A1.) Instead, you use [ColumnTitle] for the entire column (where "ColumnTitle" is the actual title of that column) and [#ColumnTitle] for the column value in the same row. So if "Cost" was the title of column B, "RunningTotal" was the title of column C and your formula for C6 was therefore =B6+C5, you'd instead use a formula of =[#Cost]+OFFSET([#RunningTotal],-1,0)] which is longer but much easier to read/maintain/debug, and if you change a column title then the formulas change too! No VBA required. Given this, plus being able change columns for the entire columns at once, plus being able to refer to other columns in other tables without worrying about cell addresses (e.g. MAX(Table1[Cost])), plus being able to style the tables so easily, plus the integration with Power-Query, and VBA support. (See learn.microsoft.com.) Whether VBA or otherwise, add a row to your table and the columns with a single column formulas will automatically carry over into the new row.

Answer 3

Not sure about Table templates or VBA but perhaps there is another option by using =ARRAYFORMULA()
For example, say you had a header row and 3 columns and wanted your last column to be the product of the first two. In cell C2 you could enter the following:
=ARRAYFORMULA(A2:A*B2:B)
This has three benefits:
Skips the first row completely
Effectively applies the formula to every row which is useful if you later decide to insert a row (your question)
Only one location to modify the formula for every single row
Although, it may not be immediately obvious where how/where the cells are being calculated. (hint: ctrl+~ may help)