Register custom spring expression in spring mvc to use with @Value annotation

I am using the spring @Value annotation to load a property into my controller from a file.

In my controller....

@Value("#{messagesProperties['confirm.priceOverride.fourWeeksOrMore']}")
public String recallOfFourWeeksOrMoreConfirm = null;        

In my messagesProperties properties file...

confirm.priceOverride.fourWeeksOrMore=You have chosen to recall historical data older than four weeks of age. Do you wish to continue?

This works but I would now like to put a placeholder in the property file to replace the word four. For example...

confirm.priceOverride.fourWeeksOrMore=You have chosen to recall historical data older than {0} weeks of age. Do you wish to continue?

The {0} specified in the properties file will be replaced with a value returned from the database which I can get using the following code...

Integer priceOverrideRetentionDays = appParamsManager.getPriceOverrideRetentionDays();

I have worked out a way to achieve what I want which is as follows...

    Integer priceOverrideRetentionDays = appParamsManager.getPriceOverrideRetentionDays();
    recallOfFourWeeksOrMoreConfirm = MessageFormat.format(recallOfFourWeeksOrMoreConfirm, priceOverrideRetentionDays.toString());

But I would like to know if there is some way I can do MessageFormat code in the @Value annotation using spring expression language. I've never written a custom spring expression function before, that would be acceptable but I'm not sure how to register it etc.

thanks for your help.

Can someone please help me with how?

thanks