plugin hook location for "ad_showthread_firstpost" template?

[john2k]

I would like to insert the results of a plugin into ad_showthread_firstpost and am looking for the best hook location to use. Everything works perfectly when I use the global_start hook, but I see no reason to have the plugin code run globally when I only need it for thread displays so the result can be shown in the ad_showthread_firstpost template.

So, with that said, can anyone suggest which hook location is the correct one to be used in this situation?

Thanks,

John