You were very close to the one-liner. :-) 
perl -i.BAK -pe 's!(<OPERATORID>)(.*)(</OPERATORID>)!$1 . substr($2, 0
+, 10) . $3!e' FILE1 FILE2 ...

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In reply to RE: Quick solutions to easy problems by tilly
in thread Quick solutions to easy problems by wardk

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