How to change phone extensions from "x" to ","

My company is deploying iPhone 5's to all smartphone users within the company. Before using the iPhones, we were using BlackBerry. On the BlackBerry, extensions were listed with an "x" for the extensions, whereas the iPhone needs an ",", for example:

Doesn't work on iPhone = 989-123-4567 x 123

Works on iPhone = 989-123-4567,123

All contacts from within Outlook sync to our iPhones. We have fixed the global address list (comes from Active Directory), however, all user-inputted contacts still have "x" within their extensions, resulting in iPhone users unable to call people with extensions. An example is a vendor outside the company.

Is there a way we can automatically change all contacts on the iPhone to use "," instead of "x" for extensions? The only ways we figured out how to do so include: 1) Manually export all contacts (.csv) & import into excel, manually changing every contact. 2) Manually change every contact within iPhone/Outlook.

Been told this question is more suited for a Microsoft/Outlook forum. However, wanted to post it in the business forum before going down that route. Being that this is most likely a common issue for other companies as well, figured I'm sure someone out there has experienced this before. If anyone has some suggestions or help, please let me know. I'm sure this has been an issue for other companies in the past as well.

Thanks,

Jordan