>>Thought I would
>
>While at it, this was the original SQL. If that version would be used, where exactly would be the place to put the required syntax to collect the distance value in the result set:
>
>

>DECLARE @Latitude Float
>DECLARE @Latitude2 Float
>DECLARE @Longitude Float
>DECLARE @Longitude2 Float
>DECLARE @Latitude3 Float
>DECLARE @Latitude4 Float
>DECLARE @Longitude3 Float
>DECLARE @Latitude5 Float
>DECLARE @Latitude6 Float
>DECLARE @Longitude4 Float
>DECLARE @Latitude7 Float
>DECLARE @Latitude8 Float
>DECLARE @Longitude5 Float
>
>SET @Latitude=47.7795
>SET @Latitude2=47.7795
>SET @Longitude=-65.7191
>SET @Longitude2=-65.7191
>SET @Latitude3=47.7795
>SET @Latitude4=47.7795
>SET @Longitude3=-65.7191
>SET @Latitude5=47.7795
>SET @Latitude6=47.7795
>SET @Longitude4=-65.7191
>SET @Latitude7=47.7795
>SET @Latitude8=47.7795
>SET @Longitude5=-65.7191
>
>SELECT Client.Numero FROM Client
> WHERE (Client.Latitude>=@Latitude-250/111.0 AND Client.Latitude<=@Latitude2+250/111.0) AND
>(Client.Longitude>=@Longitude-250/111.0 AND Client.Longitude<=@Longitude2+250/111.0) AND
> 3958.75586574*ACOS(
> CASE WHEN SIN(@Latitude3/57.2957795130823)*SIN(Client.Latitude/57.2957795130823)+
>           COS(@Latitude4/57.2957795130823)*COS(Client.Latitude/57.2957795130823)*
>           COS(Client.Longitude/57.2957795130823-@Longitude3/57.2957795130823)<-1
>           THEN -1
>      WHEN SIN(@Latitude5/57.2957795130823)*SIN(Client.Latitude/57.2957795130823)+
>           COS(@Latitude6/57.2957795130823)*COS(Client.Latitude/57.2957795130823)*
>           COS(Client.Longitude/57.2957795130823-@Longitude4/57.2957795130823)>1
>           THEN 1
>      ELSE SIN(@Latitude7/57.2957795130823)*SIN(Client.Latitude/57.2957795130823)+
>           COS(@Latitude8/57.2957795130823)*COS(Client.Latitude/57.2957795130823)*
>           COS(Client.Longitude/57.2957795130823-@Longitude5/57.2957795130823)
> END)<=250
>

Use a subselect?

Something like - untested

select 	Result.Numero,
	Result.Latitude, 
	Result.Longitude,
	Result.Distance 
  from

	( SELECT Client.Numero,
		 Client.Latitude,
		 Client.Longitude, 
		3958.75586574*ACOS(
		 CASE WHEN SIN(@Latitude3/57.2957795130823)*SIN(Client.Latitude/57.2957795130823)+
		 COS(@Latitude4/57.2957795130823)*COS(Client.Latitude/57.2957795130823)*
		 COS(Client.Longitude/57.2957795130823-@Longitude3/57.2957795130823)<-1
		 THEN -1
		WHEN SIN(@Latitude5/57.2957795130823)*SIN(Client.Latitude/57.2957795130823)+
		COS(@Latitude6/57.2957795130823)*COS(Client.Latitude/57.2957795130823)*
		COS(Client.Longitude/57.2957795130823-@Longitude4/57.2957795130823)>1
		THEN 1
		ELSE SIN(@Latitude7/57.2957795130823)*SIN(Client.Latitude/57.2957795130823)+
		COS(@Latitude8/57.2957795130823)*COS(Client.Latitude/57.2957795130823)*
		COS(Client.Longitude/57.2957795130823-@Longitude5/57.2957795130823)
 		END) as Distance 
	) Result

   where (Distance <= 250)