Well, your construct [\w|\W] is a bit awkward: anything between the square
bracket will cause a match; because you have \w (word characters) and \W
(non-word characters), you match everything (the | is not needed between
square brackets: it will be matched...)

try something like \\\w+\.xlsx?

\\[^?\[\]\/\\=+\<\>:;",*\r\n]+\.xlsx?

The regular expression above does the following for a match:

1. Begins with a backslash
2. Followed by any character not in the list \?[]/\=+<>:;",*\r\n (illegal
Windows file name characters), one or more
3. Followed by ".xls"
4. Followed by 'x' (Zero or 1 time)