Name of attached files

Dear Zoho Team,

when people attach a file to their application (e.g. a cv) sometimes the file name includes letters like ä,ü or ö. When the files are downloaded along with the provided personal information the file name has changed. For example the name of the uploaded file was "JürgenCV.doc". When beeing downloaded from Zoho the file name is now "J++rgenCV.doc". Can you explain whats going on here? Its important to me since the file name which comes with all the other personal information has to match with the actual name of the downloaded file for further automatic processing. Correcting the changes to the file names made by Zoho is pretty time consuming when dozens of file names have been changed.

Thank you in advance and with best regards,
Andreas Michel