Is there a Alt+### code for the diacritical marks like the macron and breve which

[BettyLeneFranzus]

cover two vowels? Alt0333 will produce an o with a macron above it in Office 2007 but I can not find a similar combination to create the diacritical mark for a word like boot. Please advise
The Character Map does not provide a symbol for two vowels (the same two vowels) with any diacritical mark over them so the answer given by Bert is not helpful. Sorry!