Add option to Bibliography Field Substitutions

Edit Output Style > Bibliography > Field Substitions now shows one of four options:

If the Volume and Pages fields are empty, use:<optional field>.

Add new option:

If the Pages field is empty, use:<optional field>.

or split up current option into two options:

If the Volume field is empty, use:<optional field>.

If the Pages field is empty, use:<optional field>.

Why: Some Journal Style definitions require, if pages field is empty, use Article number (Custom 7 in EndNote).

I need the reference style to appear as it appears in PubMed AMA format for epub. In order to attain that, under filed substitition i perform the below change:

If the Volume and Pages fields are emptry, use:

|. Published Online Year Date

But i need “Published Online Year Date” to appear after title and not after Journal name. How will i be able to do that. Kindly help!