The EXCEL classes 

Whilst being OK for the occassional macro, VBA has its limits for full projects. The syntax is more limited than that of VB and I've found stability problems with Excel VBA.
However, Excel is a very useful data storage medium and the Excel classes were designed to allow this use from within a VB based application.

There are two classes, ExcelApplication and ExcelWorkbook.

 ExcelApplication 

This opens Excel if necessary and creates a collection for ExcelWorkbook objects. Ony one ExcelApplication object can exist at a time.

 ExcelWorkbook 

This allows workbooks to be opened and manipulated. Books are defined as 'With Events' so that use can be made of Excel events.

The class has the following methods and properties.

 METHODS 
Name Parameters Operation
open_book Book name Opens the specified book.
clear_sheet Clears the contents of the current sheet.
save_book Saves the open book.
close_book Closes the open book.
 PROPERTIES 
Name Parameters Operation
get_book Returns a reference to the open book object.
sheet_name Returns the name of the active sheet.
get_sheet Returns a reference to the active sheet.
select_sheet Sheet name Selects the sheet and returns a reference to it.
set_sheet Sheet name Returns a reference to the specified sheet object WITHOUT selecting it.
set_range Sheet name, (r1, c1), (r2, c2) Returns a reference to the defined range on the specified sheet WITHOUT selecting it.

The class contains only one procedure for events, 'xlBk_SheetActivate', which calls a main program procedure, 'select_sheet_action', whenever a new sheet is selected. However, it is easy to add code for other events using these as templates.