Flaps stay fixed, probably up. All you have left in your control bag is the ability to change airspeed, using the elevator control, and the freedom to move to a different altitude. Only airspeed V and altitude h are at your disposal. And those only within limits. In a sense you can also choose the airplane's gross weight, W, but you'd best do that on the ground, while fueling.
Passengers strongly protest being ejected from the airplane in midflight.
In the spreadsheet's V-speed section, Part B, speeds are outputs. You may want printouts of Part B for three or four different gross weights. Stash them away in your airplane's glove box or in your map case. Part B of the accompanying spreadsheet Bootstp1.xls for a Cessna 172 weighing 2000 pounds. If you want readily-available printed output for say three altitudes and three gross weights, you'll end up with nine different Part C performance sheets.