Frankly, I think you should make a custom toolbar button for such a thing, but here goes...
(defun C:YELLOW ()
(command "-insert" "STAR")
)
This should do it. It assumes the block "STAR" is either found on a search path, or already defined in your drawing. It stops at the point of where do you want to insert, scale, and rotate.
This one asks for the insertion point up-front, then inserts the block at full scale.
(defun C:YELLOW ()
(promt "Select an insertion point:")
(setq USERPOINT (getpoint))
(command "-insert" "STAR" USERPOINT "1")
)
Depending on your ACAD configuration, you may need to supply X and Y scale...
(command "-insert" "STAR" USERPOINT "1" "1")
and rotation...
(command "-insert" "STAR" USERPOINT "1" "1" "0")
... so one of these lines might work for you. There are ways to detect the environment settings and use an IF or COND statement to decide which command sequence to use. Also note the "1" "1" "0" can probably be written 1 1 0, and using the "command" function, I know the quoted numbers will work for sure.