Grep style to apply italic overmore than a paragraph

I'm trying to create a GREP paragraph style that applies automatically italic charachter style to text between quotation marks, even if they spread over more than a paragraph.

EXAMPLE

“This is the first sentence” and it goes in italic.

“This is the beginning of the second italicized block of text that:

1.          expands over more than a line;

2.          has to keep italic up to the next double quotation marks…

…That happens to be here”.

I was thinking of something like

     ".+?"+

but, no luck, it doesn't seem to work for me.

Any ideas?

Thanks,

Guido