Delete columns that contains only numbers

I have a table that containes some data and I need to delete the columns that contains only number (Nr.,Cod,Tiraj): Nr. Autor Titlu Cod Tiraj Tara 1 Gauss Carl Aritmetica 1 297485 11454 Germania 2 Gauss Carl Aritmatica 2 297484 10254 Germania 3 Gauss Carl Aritmetica 3 297455 45872 Germania The results should be like this: Autor Titlu Tara Gauss Carl Aritmetica 1 Germania Gauss Carl Aritmatica 2 Germania Gauss Carl Aritmetica 3 Germania The columns are separated by TAB I created the table using this: .TS tab(@); c c c c c c . Nr.@Autor@Titlu@Cod@Tiraj@Tara 1@Gauss Carl@Aritmetica 1@297485@11454@Germania 2@Gauss Carl@Aritmatica 2@297484@10254@Germania 3@Gauss Carl@Aritmetica 3@297455@45872@Germania .TE