hi, Chris

I was close but the naming of the embedded picture was the trick I missed.
However, I can only get it to work for type 23, picture.
There's still no joy with type 17, icon.
I'm not quite certain what the different consequences of using 17 or 23 are
- 23 does what I wanted to do perfectly well - but for curiosity I'd be interested in beating the icons.

Is the type of source file relevant? Or the method of embedding?

icon type (17) accepts only numbers 1 to 3 as follows:
(and the "icons" are their simil to vba: vbQuestion, vbInformation, vbExclamation)

1: ? (question mark)
2: i (information)
3: ! (alert triangle)

any "icon" referring to an image, shall be type 23

hth,
hector.