My recommendation since this is a per user thing would be to store a flag in the HKCU somewhere and read/write it as needed.

Then store the quote file as a .ini in the NETLOGON and read it in that format sequentially.

i.e.

[QUOTES]
001=Wicked ways are those of a wicked mind
002=Lincoln was a penny pincher

Then in the registry set 002 as the last one read and have your code increment up from there until you reach the end number then reset the value in the registry.