You will need to specify in what software you want to do this.
You will not able to tranfer the formula to MS Word 2007. You can follow the mentioned below instructions.
Copy the data from MS Word to MS Excel.
Perform the conversion using TEXT to Column or Year(), Month, Day() function as required.
then copy past the values from MS Excel to Word.
I am not denying the fact that there can be better solutions to this problem. But with available informationi this is only solutions I can think about as of now.
Microsoft Excel help