Help with error trapping and exploding block.

If I take out the * that preceedes the block name the error trapping works as expected but when it is in the code "*PLOTSTAMP-B" the error trapping does not work. Can anyone explain why?

;; Error handling function
(defun MyExit (msg)
 (cond
   ((not msg))    ; no error, normal exit
   ((member msg '("Function cancelled" "quit / exit abort"))) ; <esc> or (quit)
   ((princ (strcat "\nError: " msg)))
   )     ; End Cond
 (COMMAND ".UNDO" "b") ;| any other code for needed cleanup |;
 (princ)
)
;; Program Code
(defun C:XREFBORDERANDPLOTSTAMP (/ *ERROR*)
 (SETQ *ERROR* MyExit)
 (COMMAND ".UNDO" "M")
 (command "fielddisplay" "0")
 (command "tilemode" "0")
 (command
   "_.-xref"
   "_o"
   (getfiled "Select Drawing to Xref"
      (strcat (vl-filename-directory
  (vl-filename-directory (getvar "DwgPrefix"))
       )
       "\\"
      )
      "dwg"
      2
   )
   "0,0,0"
   ""
   ""
   ""
 )     ;CLOSE XREF
 (command ".zoom" "w" "-1,-1" "4,7");zooms to the lower left corner of the border
 (alert "Please select the insertion point for the Plot Stamp.\n(Off of Lower left corner of the Border not the trim border.)"
 )
 (command "-layer" "N" "HAI_PLOTSTAMP" "S" "HAI_PLOTSTAMP" ""); creates and sets the HAI-PLOTSTAMP layer
 (command "-INSERT" "*PLOTSTAMP-B" pause "" "");inserts the plot stamp
 (command ".zoom" "e")
)

Thanks,

Sean