You can use BlackBerry Desktop Manager to backup the data from your BlackBerry device. Keep notice that if those emails are protected through BES, then you might violate company's policies. It's OK for personal emails. Access the download page and save the application to your computer. Install it, then connect the device and perform the backup operation. Save the files to a format that's close to Word, then use the database of Software Informer to look for an application to convert those emails to Word.