Hello, Amy-L:
There’s a setting sort of like this in the output style. While I don’t believe it’s in exactly the format you say, it will group together references, so you may want to try it.
- In EndNote, use the Edit menu to select Output Styles and then Open Style Manager.
- Type the first few letters of the style you are using. Scroll to it, select it, and then click Edit.
- If on a Mac, click the arrow next Citations, and then select Numbering. If on Windows, click on Numbering under Citations.
- Place a check in the box under Grouped References
- Save the style and close it
It will then group under a single bibliography number any citations that are always cited together. Try it… does it help?