`http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/reference/ifaces/iitemnamelimits/GetValidCharacters.asp'."
(format "%s/%s.png" mh-x-image-cache-directory
(mh-replace-regexp-in-string
`http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/reference/ifaces/iitemnamelimits/GetValidCharacters.asp'."
(format "%s/%s.png" mh-x-image-cache-directory
(mh-replace-regexp-in-string