Ok, finally I made it work - here's the simplified procedure's code that's working fine: ALTER PROCEDURE [dbo].[GetData]( @Column varchar(100), @Begin datetime, @End datetime ) AS BEGIN DECLARE @query nvarchar(1000) SET @query = N'SELECT ' + quotename(@Column) + ' FROM MyTable' EXEC sp_executesql @query END Thanks for your hint vimal_yet!

Ok, thanks for your answers! I'll try to improve the performance of the data import by merging the query and the insert together in one SqlCommand.