There might be a way if your autocomplete is sourced by a local list. If sourced by other sources like report definition, clipboard page, you'll need to take addtional steps to convert your autocomplete source to the language you want, which will involve using getLocalisedContent()
Having said that, once a "localized" value is stored in a property, consider the repurcussions of retranslating to "English" when needed.
The source for Auto complete is Data page. If i use get localizedtext function to convert the auto complete values into localized text, then the clipboard also stores the localized value instead of English. In this process an extra work needs to be done to convert localized text to English. Please correct me if anything wrong.
Is there any way to store the value on clipboard in English with localized text on UI by using the source as data page?