~$

[arhangelmihailo]

I do not know how, but my .doc file somehow converted into file with characters ~$ at the begining of the origin file name, like this:
plan2004.doc converted into ~$plan2004.doc

Now, when I open this file, I see nothing but some unintelligable characters! The origin conten has gone!!
I want to recover my origin file, but I don't know how? Why did this happen?
What does this characters ~$ mean?
The file is very, very important to me, so please, somebody help!