I don't know of a way to convert the files, but you should be able to import the data. Then you can set up the needed relationships, scripts, layouts etc. in FileMaker to work with your data in ways not possible with Appleworks.
Look into what methods exist for exporting data from AppleWorks. If you can export into a tab delimitted file or comma comma separated values (csv) you can then import this data into Filemaker.