No, you can't directly perform a hardware reset from software using any digital pin operation. Even if you wire a digital output pin to the reset pin, the output pin will turn off too quick to completely reset the chip and the AVR datasheet says you can't do it that way. There is a way to do a reset using the watch dog timer, but it's somewhat complex and may not be compatible with the Arduino bootloader program, at least that's my take away on past postings.
So why do you need to perform a hardware reset? I think that there is a 99.99% chance that there is another way to structure your program to accomplish what needs to be accomplished.
Why don't you post your sketch (use the insert code # button) and I'm sure someone here can help you with it.
Lefty