Are you talking about actual assembler code, as written and commented by a human?
Which is what the tool you referenced would seem to need.

Or the disassembler output (devoid of comments) as output by say dumpbin ?
In which case, you're pretty much hosed.

Whilst decompilers exist, the result is not something you would want to maintain (or look at). Everything will be called var1, var2, var3 etc.

I am talking about actual assembler code, as written and commented by a human. And the conversation a big code is my job in the probation. Do not understand wrong, I do not try to use a dissambler output and stole someone's work.

I want a program because at first part they want me to convert a hex code to assembly, secondly they want me to find is there any way to reach to higher level code to assembly code. And my real objection in probation is protect a program ( in .exe position ) to steal source code. I want to learn how these converters work than I will try to find a solution to my problem.

If you are suspicious about my truth, you can explain me just how these converters work and how we can prevent our codes from these type of steals.

Thanks anyway.
I am waiting for your response.

There are two reasons for writing in assembly (besides having fun!) and those are to take advantage of the speed possiblities and/or interface to something not otherwise easily interfaced to.

Hand-coded assembly ususally consists of a few instructions (<=25) so it's not all that difficult to grasp the logic.

It could be that the assembly code you have is the startup code for your program and then I recommend not touching it.

If the code does not interface anywhere and appears to be written solely for speed, it should be relatively easy to convert it by hand to C code.