Lookup Table for all Sourcetype

Hi All,

Quick question, in Manager » Lookups » Automatic lookups » Add New on Apply to drop down box, we can select from SOurcetype, source, or host. If I choose any of the choices, can I put * on the sourcetype field. The reason is the lookup table that I created meant for any sourcetype, and any host those are currently indexed by my SPlunk. I tried before it wouldn't do the trick. If possible, do I need to put other character value?

Please advise on this

Thanks