I agree, that is an odd file name. I am not sure where the "~" is coming from. I am using Lookout 5.1 on a Windows XP machine. If I open a new process and use the default process name "Process1", the same name is appears in the "File name:" field of the "Save Process File As..." window when I navigate to File >> Save As. Even if I choose another name for my process, that name is then used as the default file name when I go to "File >> Save As."
If you save your process with another name, such as "myprocess.l4p", does the same default name appear when you go to "File >> Save As"?
I have seen the "~" character used in other applications when a file name exceeds the maximum length but I do not recall having that problem on newer OSes like Windows 2000 or XP. I tried to save a process with a really long random file name on my machine and I was still unable to reproduce the behavior you are seeing.
What version of Lookout are you using and what OS are you running. If your process is running on an older OS or you are using an older version of Lookout, it may be that the file name is limited to fewer characters.
Aaron C. National Instruments Applications Engineer