I need a scrip that will export selected fields of the current record to a .csv or tab-limited txt file to import into Moneyworks Express.

I have little knowledge of scripting and tried using "Export Field Contents" but this wanted to overwrite the destination file each time a field was exported.

You want File>Export Records or the script step Export Records. It'll export the found set. You could script the export so that the file name is unique by appending a timestamp to the file name.

"Selected Fields.." So you want to make several exports of the content of different fields on just one record, and then import each fields content as a record? or what?

If this is the case you could make a calculated exportField that is formattet the right way with the data from the wanted fields ad export this.

Or if the fields are decided at runtime . add them to the export field one by one and then export it.

Not at all sure that this is what you want, but thats what I get out of your post :)

Why do you suggest a "calculated export field" instead of Export Records? I would think that the accounting program needs the same data fields each time.

Sorry, didn't make myself clear. When I create a record in FM I want a button on the layout marked 'Export' that will copy a selection of the fields in that one record so ao I can update my Moneyworks account record. The only fields i need would be the unique number, Name, and Address fields of the current record exported into a single file for importing

Why not use the Filemaker plugin that they have available? Link I would think this is a more stable way to communicate btw the two programs than text files.

I have installed the plugin but not sure how and where to access it in FM

Plugin are typically found as External Functions in the calc engine. Start a new script, and add a Set $var script step so that you can create a calc. Have you done their tutorial?