Long ellipses are actually ellipses with a period tacked on the end to indicate a writer has chosen to leave out material at the end of the sentence. To add long ellipses in Word, you insert ellipses and then add a period to the ellipses you just inserted.
Simplest Method to Insert Long Ellipses
Open your document. Place the cursor where you want to inert the long ellipses, click on the "Insert" tab on the Word banner and click on "Symbol" on the far right of the tab. When the window opens, click on "More Symbols." In the Symbol window, click on "Special Characters" and find the ellipses about half-way down the list. Click on "ellipses" and then click on "Insert." To make this a "long" ellipsis, you have one more task: at the end of the ellipses you inserted, add a period from the keyboard.
To use "Auto Correct" to insert ellipses when you type "..." (three periods), from the "Insert" tab go to Symbol. In the Symbol window, click on "Auto Correct." Next click on "…" and then click OK, which adds this ability to your auto correct entries. The shortcut key for ellipses is "ALT+CTRL+."