C# Help: How to safely modify Windows Forms Designer code?

I'm writing a Windows Forms project in C# using Visual Studio 2010 Express. I need to make many iterations of a panel, each of which is identical except for name and position. I also need the code to be able to make variable numbers of these (example: one time it runs, it puts 40 on a form, the next time, it might need to put 100 on). I've figured out how to come up with a way of calculating all these properties, but I need a way to actually put them on the form. I've tried building an instance of a class with all the panels I need inside the initialize component routine, but that doesn't work. I've tried creating a second partial class of the Form, but then it gives me this: "The type Form1 is made of several partial classes in the same file."

Any suggestions? Please be detailed in your explanations, I've only been programming for a year or so, and Windows Forms are new territory for me.

Thanks!