Custom Fields Query

Im trying to pull a custom field from a page to a template and run into a little difficulty

I am currently using the below query to query my tag ‘autoshows’, and would like to change the query to use the custom tag field used on my page

‘<?php // this is where the upper sub blog gets printed
query_posts(‘showposts=4&tag=autoshows&orderby=title&order=ASC’); ?>’

I have made a Custom Field called TTAG
and are trying to get the query to show posts where CustomField.TTAG = my CustomField.Value

all help would be appreciated… cheers