You can try to seek assistance in a translation site such as <http://www.proz.com>.
This is a global site connecting clients and translators from around the world. Although there are few professional translators who understand advanced mathematics, such creatures may exist if you seek translation from a common language like French.
You can register at the site and offer the job with all your conditions. Then you select the translator who suits you most. 

I would not expect a high-quality result, but you can help the translator by providing her/him with the terminology of the subject field.

The down side is that it can cost you several hundred $, depending on the length of the paper.