We don't do % of lever movement. All percents are based on N1. I didn't want to give a specific N1 because I'm not familiar with the CFM-56 at all. On the CF6 (What we use on the whale) we spool N1 up to 70% N1 then press TOGA. Stand them up is a generic term thrown around for spool them up. As a physical reference it looks like you stood the thrust levels vertical. Like they stood up. :-)
The reason I said be quick about using the TOGA switch is at 50kts the Autothrottle is inhibited until passing 400'. This is in the actual aircraft...I'll have to try the sim to see if it works the same. Giving all the problems I had trying to figure it out a couple years back I'm guessing it is the same. PMDG does an outstanding job of accurately simulating the real deal. What I'm getting at is if your looking for this magical 40% and trying to be as accurate as possible, and you pass up 50KIAS and you haven't pressed TOGA...your going to have to set takeoff thrust yourself. And then passing 400' cycle (turn off then on) the Autothrottle switch. You should be in VNav so that should re-engage the Autothrottle. BTW, I don't remember if I mentioned this, but before you take the runway, Autothrottle on, verify LNAV, VNAV armed and check your MCP Altittude.
I hope I'm not making this more confusing as I go.