Please HELP SMB over WAN

Hi all..
I Have Linksys E4200 which Tomato Shibby installed.
I attached an USB disk. And activated Samba File Sharing.

I want to access this Disk over WAN. I know the security risks about samba sharing over WAN.
I tried to port forwarding for UDP 137-138 and TCP 139,445 to ROuters IP itself. But no sucess..

Could someone please tell me how to I manage to access this USB disk attached to Router over WAN by writing "\\myDynamicDnsDomain\SharedFolderName" on windows "Run" Box.

Thank you in...

Please HELP SMB over WAN