How to run an .exe file (Install Wizard)

I've been thrown into Powershell knowing nothing about it and having to learn via the web alone, so please be kind.  I'm putting together a script that will build a Windows 7 PC (SP 1 with just the basic operating system and Admininstrator account), adding user accounts, applications, printers, FTP, SSH, et al as it goes.  The very first thing I need to do is install AutoIt, which will be used to run some portions of the install.  The script is autoit-v3-setup.exe which brings up an Install Wizard.  Since it's an .exe and not an .msi, how do I have Powershell run through the Wizard (defaults all the way) and finish before moving on to the next item?

Thank you