Artificial harmonics with sounding pitch in parenthesis

[Tom Hall]

Hello List

is it possible to combine harmonics notation with a small stemless parenthesized
note indicating the sounding pitch of a string harmonic? 

Something like 

<a e' \harmonic  \parenthesize e'' >

-but also including a small stemless notehead (\tiny?) for the e'' This is
common in C20th notation. 

I'm not familiar enough with lily tweaks and complex syntax to know how to
combine these properties, so any help appreciated.

Regards

Tom