Yes it is possible e.g I have ms word file 2007 version It is possible to open it and save it as 2010 ms word.

Lower version (2007) can open in latest version (2010) but latest version can't open in old.

it is possible to open lower version in higher version...but it is impossible to open higher version in lower version

YES IT IS POSSIBLE USE THE SAVE AS COMMAND TO SAVE THE DOCUMENT IN MS WORD10 AND THEN OPEN THAT FILE

BUT FOR THAT U HAVE TO INSTALL MS OFFICE 10