The in-text citation is an abbreviated form (such as “Author-Date”) that corresponds to the bibliographic entry so you’re asking to perform a function that cannot be done by modifying the EndNote citation template.
But a workaround would be to insert the citation then edit the citation to “Exclude Author” and “Exclude Year” which renders the citation invisible (but allows the reference to be listed in the bibliography. Then manually type-in the desired bibliographic entry.
Another alternative is to select and then ctrl K the record in the endnote library display, and then ctrl V to paste it into the document. This renders the citation as it would be formated in the bibliography, but it is not “linked” as a field. that is what I would do. you can also insert an endnote citation as described by CrazyGecko, so it appears in the bibliography as well.