1. VBA: Your First Macros

VBA (Visual Basic for Applications) is a programming language built into desktop Excel. A macro is a procedure that performs actions for you.

• Turn on the Developer tab. Record Macro turns your clicks into code, which is a good way to learn;
• open the editor with Alt+F11;
• save a workbook with macros as .xlsm;
• VBA doesn't work in Excel for the web. There, automation means Office Scripts.

Sub Totals()
    Dim cell As Range
    For Each cell In Range("B2:B10")
        If cell.Value > 100000 Then cell.Interior.Color = vbYellow
    Next cell
    Range("B11").Formula = "=SUM(B2:B10)"
End Sub

This macro fills cells greater than 100,000 with yellow and writes a sum formula. Note that in VBA, formulas are written in English with commas (.Formula). For formulas in the user's local language there is .FormulaLocal.

Security: a macro is a program. Don't enable macros in files from unknown sources.