We need a custom search form that will search our catalogue for a custom query.
Standard form is as follows:
I need to add an entry to search a single index 'lh' (local headings). Here is a url that searches that index for 'twins':
The form should add the 'lh' to the string so the user doesn't have to.
I'm assuming that since the url works, a form can be programmed to output a similar string, which allows the user to input the desired search term (eg, twins in the example above).