Sarczar,
A little confusing. Toolbars have little bitmaps (.bmp) files, and can be loaded, floated, moved on screen..thumbnails imply 'small' images (slide files .sld) that can be shown using the ***image section of a menu....pulldown implies the top menu bar would have a "string", and picking would expand to be a 'menu' (text based) to choose items from...
I suggest you make up generic sample trims, make .sld files (mslide), produce a slide library (file.slb), using SLIDELIB.exe, and placing the visible (thumbnails) on the ***image section of the .mns file. For each item, just do a lisp load, and pass it the name of the 'block' insert desired (example)..
***image
[Trim type 1]^c^c(setq blk "trim1")(load "insert_trim");
..
Then make up the insert_trim.lsp file, with the busy parts..
i.e.
(command "_-insert" blk pause """""")
(command "_explode" "l" "")
(command "_extrude" ...
or such..
Give it a try, and keep us posted.
Bob