Windows Firewall doesn't support wildcards, therefore I'm thinking using a batch file would probably be the quickest way. Batch files aren't really my forte, however as an example maybe something along these lines.
1) Paste ALL the following into NotePad (including the last line that's hidden from view) and obviously edit to show the folder path where the applications that you want to block are.
for %%G in ("C:\Program Files (x86)\Test Folder\*.exe") do (
netsh advfirewall firewall add rule name="Blocked With Batchfile %%G" dir=in action=block program="%%G" enable=yes profile=any
netsh advfirewall firewall add rule name="Blocked With Batchfile %%G" dir=out action=block program="%%G" enable=yes profile=any
2) Save the text file and rename it to BlockInOut.bat
3) Right-click BlockInOut.bat and run as administrator.
4) Check your Inbound and Outbound firewall rules afterwards
Note: Before carrying out any of the above, I'd recommend that you open Windows Firewall With Advanced Settings in the advanced view. Right-Click and select 'Export Policy', then save it somewhere safe. This way in the event of any problems, you'll be able to import your policy again to reset it back to how it is currently.
Obviously be aware that Windows Firewall won't give you/the user any indication if or when it's blocking connections, unless you specifically set up Blocked Connection logging in Event Viewer.