Sorry to dig out this old thread but I banged my head on this the whole morning so I thought I'd share my solution to help you out maybe:
As a long time user of proxy.exe I went to open a bunch of pdfs with .bat and proxy as usual - just to be stomped this time by the whole thing not working...All i get is silence. Testing the renamed proxy with clicking works, FlashPlayer refuses to open my pdf >
So I dug out an old project of what I knew was working and entered my new path in the bat: Tadah, runs shmooz!
Renamed the bat and exe to resemble the pdf name and the whole thing facepalmed again-wtf!
Not to torture you any longer heres the solution:
The filename , hence the name of the bat and the exe now contained a "-" character causing the failed exec command. soon as I removed that from both the exe and bat names I was golden again. the filename inside the bat still contains this infamous little character but that doesn't seem to be a showstopper...