SQL Server EXEC sp_executesql

DECLARE @parameters nvarchar(max)
SELECT @parameters = '@FromDate datetime,
@ToDate datetime,
@Adults int
@CountryId int'

EXEC('EXEC sp_executesql N''' + @sql + ''', N''' + @parameters + ''',
@FromDate = N''' + '2010-01-01' + ''',
@ToDate = N''' + '2010-01-10' + ''',
@Adults = N''' + 2 + ''',
@CountryId = N''' + 123 + '''')