Visual Basic for Applications (VBA) is an implementation of Microsoft's Visual Basic which is built into all Microsoft Office applications.
Support for VBA is not complete, but it covers a large portion of the common usage patterns. Most macros use a manageable subset of objects in the Excel API (such as the Range, Worksheet, Workbook, etc.) and the support include those objects, and the most commonly used method/properties of those objects.
Loading Microsoft Office documents with executable VBA macros
Choose LibreOffice - PreferencesTools - Options - Load/Save - VBA Properties and mark the Executable code checkbox. Then load or open your document.
Running VBA Macros
Run VBA macros in the same way as LibreOffice Basic macros.
Since support for VBA is not complete, you may have to edit the VBA code and complete the missing support with LibreOffice Basic objects, statements and functions.
Editing VBA Macros
VBA macros can be edited in the LibreOffice Basic IDE.