Create new file po in cakephp merge with old file po

I crea开发者_运维百科ted a po file by cake command. However, after editing some template file, I have to insert more string for translating. How could I created new po file by cake command with old translated string in old po file? Thanks and best regard.

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Hopefully you are using source control, in which case it is easy... Svn or git will handle this for you.

If you are not, you're in for a long night of manual merging and hair pulling.