Lyircs melsima line ending in interpunctation

[Nils]

Hello,

my publisher wants me to place interpunctation at the end of melisma underlines:

A -- le -- lu -- ja __ _ _ _ _!
instead of 
A -- le -- lu -- ja! __ _ _ _ _

The problem is that _! is not allowed by lilypond and __ ! takes an extra 
syllabe for the !.


Any known solutions? And if not: I find it strange to make it like this. Do you 
know reasons that speaks against __ _ _! which I can tell my publisher?

Nils