Can't find example of required formatting; options to create a format?

I’m under a deadline and would appreciate any help. Using Endnote X2.

A publisher has requested very specific formatting but is unaware of a default endnote style that will accomplish their style. I can find components of the style by selecting a few but even when I’ve manually converted all the citations such that the year comes after authors, and author list is truncated at 3, endnote keeps reverting back to the default style and my tedious work is lost. Is there a drop down menu from which I can just specify my options?

ALternatively, is there a format which uses brackets [10] in text, truncates authors to et al after 3 authors if authors >=7 but lists them if <=6, and lists the year after authors in parentheses, and uses no bold or italics?

At a minimum, how do I save the document after manually adjusting the references without endnote changing it all back?

For the last option, on a copy, remove field codes and it will let you edit to your hearts content. 

But  Masaaki’s styles collection in this threadmight help you find a close match. Also, if you Edit>Output Style> Open Style manager, you can Preview the bibliography output for each style you have installed, using the Sytle Info/Prview button at the bottom.  Finally make sure that endnote hasn’t already generated a style for the journal/publisher in question by searching styles here.

When  you have one that is close, you can adjust the number of authors that are shown by editing the style.    It is always best to start with something and edit it rather than trying to create it from scratch.  (and much better than manually making changes! 

Endnotes Help files (search for “Additional Style Formatting Options”) tells you how to edit the number of authors showing  and the options exist for both Citations and in the Bibliography (and footnote) templates. For example - the help file says:

Abbreviating the Author List

Some journals require that you abbreviate the list of authors, using “et al.” or an equivalent, after a certain number of authors. The “Abbreviated Author List” section of the Author List panel allows you to specify the number of authors needed to trigger this abbreviation, how many authors to include in the formatted reference, and what the abbreviation should be.

List all author names
Choose this option if you do not want to abbreviate the author lists.

If ___ or more authors, list the first ___ author(s)
Select this option and fill in the blanks with the appropriate numbers if you would like the list of authors abbreviated.

and abbreviate with
Enter an abbreviation such as “et al.” You can italicize the abbreviation by selecting the “Italic” check box in the dialog.

OK, will try. Thanks for the help!