Non-square to square....(looked everywhere!)

Question

Guys, I know this is an old question, and I did find a lot of discussions about the need to change non-square pixel widescreen PAL footage to square pixel for some uses, BUT, I still simply do not understand HOW to do it!
Here's the story so far: I've filmed some video in widescreen. I've captured that video in Premiere Elements 7 and it looks fine. It fills the 16:9 frame and looks normal. A nice widescreen scene in PAL.
Now, I want to take that shot and temporarily put it into an app called Particle Illusion, so that I can add some particle animations over the characters. But Particle Illusion will only accept dv footage as SQUARE pixels.
So, here I have this shot sitting as a widescreen shot in the Timeline in PE7, and I want to convert it, (temporarily), into a shot with square pixels.
What exactly do I have to do? What butttons do I click, what app do I use, what feature do I access..... to make this footage acceptable to an app that only accepts square pixels???????? How do I actually accomplish this thing??!!!!!
And how do I get it back afterwards, since once I've added the Particle Illusion effects, I want to be able to take that footage back to PE7 and re-insert it as a widescreen scene in my film.
Anyone who can explain this to me in words of less than four syllables will get a free ticket to Disneyland.
Well, I might have been exaggerating about the free tickets part...
BUT PLEASE, this seems like it should be soooo simple, but I just don't know where to start!!!!
Thank you, thank you, thank you...in advance....
Kurt.

Answer 1

Particle Illusion will only accept AVIs, Steve. And, of course, only with square pixels.
In PE7, I noticed the "Advanced" option is only available when you Share a clip as an Mpeg, but not when you want to Share it as a DV AVI.
So, I clicked on the Mpeg option and then the Advanced option and found the "square Pixels" setting. So then I was able to Share it as a square-pixel Mpeg2. 
Now, I still had to make it a square-pixel AVI. But none of my other apps would do that for me. Virtual Dub won't accept Mpeg-2s, Quicktime Pro won't save as AVIs, my Any-Video-Converter tells me that it converts it, but then the converted file vanishes into the ether.....
I opened it in Streamclip, and finally managed to export it as an AVI. But it came out weird, with the bottom half of the frame chopped off, the quality really poor, and in a "letterbox effect which allowed the Particle Illusion effects to spill over into the black horizontal bars. There are so many settings for exporting as AVI, and I've obviously picked the wrong ones....
I'll just have to try every setting there is, and see which one works!
Whew! They say Life wasn't meant to be easy........
Thanks, anyway, Steve.