Thanks for the links!  However, I don't think they'll serve my purposes for two reasons:
1.  They're for nighttime only, whereas I'd want my tot to wear them all day.
2.  They look exactly like "normal" underwear, whereas training pants should lie somewhere between diapers and undies.  At the very least, the training pant should be divided between the "center" (reaching from the center of the front though the crotch up along the center of the rear to the top; basically where the pant will absorb any "accidents") and the sides (which are normally stretchable (like "grown-up" briefs) and lack the straps of a "velcro" diaper.  The ones you linked to lack this

Why do I mention all this?  Because the only way to clean up a toddler Sim is to change his diaper (regardless of whether it's been "used" or not), even if his potty training has been a complete success.  So, I can't technically get my toilet trained Sim tots out of diapers (while they're still toddlers, that is), I'd like to give them the next best thing.

I though the pic from the old Pull-Ups ad demonstrated what I wanted pretty well, but apparently it wasn't.

Could someone please make me some training pants for toddlers?  Here's the general idea I have:

While, ideally, this would involve a completely new mesh, I think I could settle for a retextured diaper mesh or a "on-body" brief texture, as long as it illustrated the "underwear-sides, diaper-middle" model of training pant I'm looking for.

So, does anyone want to do this?