Existing word lists can be imported via cut-and-past from other Windows programs such as Excel to the Selingua Dictionary Editor.
All you need to do is to create an Excel spreadsheet that has the same 11 columns as the dictionary editor. Fill the 11 columns with words and difficulty levels (if you do not want to fill out the words in all languages, just leave some cells blank). Then select the words and press ctrl-c. Switch to Selingua Columns and press ctrl-v. Done! :-)
Above, you see the Excel spreadsheet, Below, the same data pasted into the Dictionary Editor
