Question

Is it possible to call a stored procedure within a IN clause?

Select field0, field2 FROM Table
WHERE field0 in (exec storedproc)

The reason for stored procedure is because of the complexity of it

Answer 1

You could have to use OpenRowset to achieve this.

Select Field0, Field2 From Table
Where Field0 in (
                SELECT Field0 FROM OPENROWSET('SQLNCLI', 
                             'Server=SERVERNAME;Trusted_Connection=yes;',
                            'EXEC StoredProc')
                )

In order to do this the following options must be enabled on the server:

sp_configure 'Show Advanced Options', 1
GO
RECONFIGURE
GO
sp_configure 'Ad Hoc Distributed Queries', 1
GO
RECONFIGURE
GO

If it isn’t possible to change these settings then another option, as discussed with Martin in the comments, is to populate a temporary table.

e.g.

declare @t table
(
Field0 int,
Field1 varchar(100)
...
)

Insert Into @t
Exec storedProcedure

Select Field0, Field2 From Table
Where Field0 in (
                SELECT Field0 FROM @t
                )

To insert the results of the stored procedure to a temporary table the definition of the temporary table must match the results of the stored procedure exactly.