Q: Thunderbolt Display + MacBook Pro w/out a Thunderbolt port?

You need an adaptor for Thunderbolt to the video port on your computer.

No. I don't think your computer has a VGA port. Exactly which model do you have?

Yes. You'll find it at the online Apple Store.

Sorry, stupid me. Thunderbolt and Mini-DisplayPorts are the same.

Mini DisplayPort display must be last in a Thunderbolt chain

Apple Thunderbolt cables and adapters

Thunderbolt ports and displays- Frequently asked questions (FAQ)

You must have a TB port to use the TBD.  Mini display port will not work.

Have found this that i think should help you.

Using the Apple Thunderbolt Display:

16. What are the system requirements for using my Apple Thunderbolt Display in OS X?
17. What are the system requirements for using my Apple Thunderbolt Display in Boot Camp?
18. How many Apple Thunderbolt Displays can I use with my Mac in OS X?
19. How many Apple Thunderbolt Displays can I use with Mac in Windows 7 or 8 with Boot Camp?
20. Can I connect a Mini DisplayPort display to my Apple Thunderbolt Display for computers that support using more than one display?
21. Can I use an Apple Thunderbolt Display and an iMac in Target Display Mode to act as two additional displays for my Thunderbolt-equipped Mac?

If your computer does not have a Thunderbolt port you can't use a Thunderbolt display.  There are no adapters or converters that will help.