here's a little util to send keys to npvr from cmd line[batch,etc]
for compound keys such as control-q use:
^=cntrl !=alt +=shift #=windowskey
F1={F1} etc.
so pause is control-q = ^q , alt-f4 = !{F4}
these are same keys as autoit send keys list..
type "sendkey-npvr ^q" to make it pause from batch..