Column Alias Names and UNION error

Hi

I need to execute this SQL

SELECT NULL AS 'county' UNION select distinct [county/department] as county from COUK_hotels WHERE source = 'activehotels' AND [county/department] NOT LIKE '%london%' group by [county/department] having count([county/department]) > 5 order by [county/department]

The first part is to shove a first result 'NULL' into the result set.  Don't ask me why - the ASP code just needs it ok!

If I run each query separately it works fine:

SELECT NULL AS 'county'

and

select distinct [county/department] as county from COUK_hotels WHERE source = 'activehotels' AND [county/department] NOT LIKE '%london%' group by [county/department] having count([county/department]) > 5 order by [county/department]

But when combined I get an error Invalid column name 'county/department'.

Is there some way of encasing the query with some characters to avoid this?