It depends on server. Bank system is an extra feature on some servers so it can be off on few, depends on admins.
So first of all you need to type "!commands" in chat while playing on chosen server and check out if you can find "!import" and "!export" command on commands list there. If so you can be sure bank system works there and you can "!import" back your exported points :)
One thing you need to remember is that you have to be logged-in with your CryMP.Net nick before entering server (use login password and press Enter in console or put it in autoexec of your game like tutorial shows here: http://crymp.net/tutorial.php
- "Permanent" way). Otherwise you (your network ID) won't be recognized by server - so you won't be able to export or import your points back. But you probably know this already because you're listed in statistics of network so you know how to use your ID.
Anyway. Run some tests and have fun.