Invalid unicode sequence error ("u")

I have a string which consists of a DOS path something like "\sample\user_data\example".

The "\u" in "\user_data" above gives an invalid unicode javascript
error in IE and hence my page isnt displayed.
Hence I wanted to replace "\u" in the string with something like "\
u"(space u)as i was not able to escape it. This also does not work as
java too does not allow "\u" and gives "Invalid unicode character
sequence" error when i use it with replaceAll.

Que 1: Can i escape the \u character some how?
Que 2: How can i replace all "\u" character in a string with something else like "\ u"?

If that is for Java,

You can declare that in StringBuffer and by using StringTokenizer , you can
separate "\ u".