Yes, it is possible.
Check out article Q247370 on the MS Knowledge Base..
>Is it possible to recover the return value of a SQL Server Stored Procedure using SQL Passthru? E.g. if I execute a SP from SQL Query Analyzer:
>DECLARE @ret int
>EXEC @ret = MySQLSvrStoredProc
>PRINT @ret
>I want to recover the value of @ret using SQL Passthru. Is this possible?
>
>Thanks,
>Bill