If you need a specific file extension to open in a native application you can create the association with the cxwinassoc tool. For example if you're using IE7 and you click a PDF document IE will complain it can't open that file (Acrobat isn't installed) even if you have Acrobat installed in the native Linux OS. You can create a mapping from Crossover to the native program by opening a terminal and running
cxoffice/bin/cxwinassoc --bottle bottlename --extension .xxx /path/to/tool
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