ORA-06502 when running dde execute command

From: Iversolis <amsolis_at_transco.ph>
Date: Mon, 12 Jul 2004 02:29:43 -0400
Message-ID: <e8174a4d6a05fbc3969597566fe853de@localhost.talkaboutdatabases.com>

i'm trying to read data from excel to Oracle forms and i use dde package to do so. i get successful when the file i am accessing is explicitly stated. but when i tried reading a file specified by the user, i get ORA-06502 error. Why is this so? How do i solve this? Thanks. Below is my script:

:block3.text_item48 := get_file_name('\\NOD021\index\');

APPID := DDE.APP_BEGIN('c:\program files\microsoft office\office\excel.exe', DDE.APP_MODE_MINIMIZED);

  WHILE NOT conv_established LOOP      
    BEGIN   convid           := DDE.INITIATE('excel', 'system');        
	        conv_established := TRUE;      
    EXCEPTION        
	  WHEN DDE.DMLERR_NO_CONV_ESTABLISHED THEN
	        
	        conv_established := FALSE;

END;
END LOOP; v_filename :=

'[OPEN("'||LTRIM(RTRIM(:block3.text_item48))||'")]';

DDE.EXECUTE(convid, v_filename, 10000); Received on Mon Jul 12 2004 - 01:29:43 CDT