Method 1:
From the Initial screen on launching ACE:
Select the program you wish to export under the "Projects" list then click the "Export..." area.
This will present you with a Save Dialogue box. Enter the name and select the directory where you would like the project to be saved.
Method 2:
From within an already opened project:
Click the "Export" menu item under the "File" Menu.
This will present you with a Save Dialogue box. Enter the name and select the directory where you would like the project to be saved.