C Sharp :: Opening A File By Using The Extension?

The code below is used to return a file path.

 private string BrowseJournalFile(string startRelativePath)
        {
            string str = "Journal files (*.log)|*.log|All files (*.*)|*.*";
            return PathTools.BrowseFile(startRelativePath, str, this.RootPath);    
        }

So once I click browse I get something like "E:New Files" But there is this .log file in this folder which I want to automatically store in this path.

Right now I have to click on this .log file and then select open. Is there a way I can directly load the file.I have been trying to use the FileStream but no luck.