You should use a LEFT JOIN form the first query to the second. There is no reason to use RIGHT JOIN at all

>I have a query which selects all vehicles from my database
>

>SELECT a.ccompania_id as cia,'*' as oficina, a.cproveedor_id as Movi, b.cvehiculo_placa as Placa,b.cvehiculo_chofer as Chofer
>  FROM [bdmain].[dbo].[_proveedor] a,[ventas].[dbo].[_vehiculo] b
>  where ctipo_proveedor_id='05'
>and cestado_prov_id='A'
>and a.cproveedor_id=b.cproveedor_id
>

>and another one wich summarizes all the customers and orders the vehicle has to deliver.
>

>select cid_transportista, COUNT (distinct cid_clie) As clientes,
>	COUNT(*) as Ordenes ,SUM(npeso_total_documento) as peso,
>	MAX(cnro_guia_remision) as guia
>	from _movimiento_ventas where cestado_documento_id='I' and ctipo_documento_id in ('FA','BO','TK') group by cid_transportista
>
>

>
>I need to join both querys into one, but showing all the vehicles even if they don't have any order to deliver. I'm trying to do a right join but it does not seem to work on grouped tables. Any help?
>TIA