sp_executesql

declare @i1 int, @i2 int,@Sql1 nvarchar(max)
  set @Sql1 = N'select @i1 = 1,@i2 = 2'
  exec sp_executesql  @Sql1, N'@i1 int out, @i2 int out', @i1 out, @i2 out
  print @i1
  print @i2