Yes you can. I'll break down the setup into two steps.
1. Searching through the ZIP file.
Make sure you have the ZIP format activated so that FileLocator Pro will read ZIP files as if they are sub folders:

Next try a very simple search to see if the ZIP file is being read properly:

2. Search through the zipped PST files
Activate PST searching:

Then again try a very simple search just to check that the PST files are being searched:

Now the PST files are being searched you can use the File name to search the subject of the email and Containing Text to search the contents of the emails, ie
File name: <subject>
Containing Text: <email contents>