Here's a quickie:
(defun c:exportblocks (/ blk blks x dir)
(vl-load-com)
(if (setq blks (vla-get-blocks (vla-get-activedocument (vlax-get-acad-object))))
(progn (setvar 'filedia 0)
(setq dir (strcat (getvar 'dwgprefix) "_ExportedBlocks\\"))
(vl-mkdir dir)
(vlax-for blk blks
(if (and (not (wcmatch (setq x (vla-get-name blk)) "*|*,*`**"))
(= (vla-get-isxref blk) :vlax-false)
)
(command "._-wblock" (strcat dir x) x)
)
)
(setvar 'filedia 1)
)
)
(princ)
)