Excel/VBA – specific sheet to sheet copy

How do I allow a user to select a cell while my macro is running? For example, the basic “sum” function in excel allows the user to choose what range of cells to add.

What I’m trying to do is run a macro that will copy from one user selected range to another user selected range on another page. The problem is that there will be any number of pages and the title of these pages will vary.

Can anyone help?