Rename a special filename

I have a file with filename: 20151231-  Newyear -12471010.html
A hyperlink to this file looks like: 20151231-%25F0%259F%258E%2587 Newyear %25F0%259F%258E%2587-12471010.html

Now I want to rename this file. I tried:

sub ChangeName()
Dim FileName as string
Filename= dir("20151231-*")
name Filename as "Newyear.html"
end sub

But this fails , possible due to the fact that Filename becomes: 20151231- ?? Newyear ?? 12471010.html

How to solve this problem?

With kind regards

Jan Lichtenbelt

PS. Now with code tags. The question remains the same