Destination url: characters not allowed

[misciab]

I'm promoting a site with urls containing 'è', 'à' (content management platform) and I can't use the right landing pages for the campaign.

Does a list of not allowed characters exist?

Thank you
Misciab

[misciab]

Anyone out there can help me? :(
I wrote to Google adwords support, no answer.
I want to maximize the ROI and need to use the right landing pages.

thank you
Misciab