Hi. Sorry if this is a stupid question, but I just felt I should ask;

I'm new here, and so I don't have any resources beyond the basics which come with the account (and homebrew stuff). However, I'm not new to D&D, and have several sourcebooks in physical form.

So, I was wondering; is there any precedent for players using characters made externally to DDB (by which I mean characters compiled using character sheet PDFs rather than the DDB character creator) in online campaigns? Just so I wouldn't have to buy the books again if I wanted to play in an online campaign.

Thanks in advance.

(P.S. Also, sorry if this is the wrong place to post this, I couldn't see anywhere else which seemed quite suitable.)

It's a very common question.  The answer is no, there's no way to directly import character options from a character sheet made elsewhere into the DDB.  Homebrew stuff is basically the answer outside of buying content (FYI you don't have to buy entire books to rebuild a character, subclasses, races etc. are available for piecemeal purchases as well as a la cart bundles from most of the books, I think all but the most recent one).  The homebrew subforum of this board is very helpful in supporting players trying to get what they own in hardcopy into the character builder via home brewing.  I stopped buying DDB books a few years ago (maintaining a master tier to share my content and maintain campaigns), and basically homebrew new content from both WotC and 3rd party as I need it (I've run Humblewood on DDB via "my homebrew collection").  It takes elbow grease,  but it is doable.  

And if you've got a campaign group set up on DDB, you can enable content sharing so long as someone's got a Master tier subscription and someone else has the book.