Without more then Germany on the doll, there is no way to know who made this. Germany was a major country that porcelain dolls were made from during the 1800's early 1900's. The Letters and numbers are mold numbers. If you are liking a current market value I can do that for you based in some pictures and a size.
We do one item per question. Without a makers name or mark there is no way to know what company made this doll. The Government requires the country of origin to be on an item imported to the US. The doll probably at one time had a tag on it that indicated the maker. As I stated there were many doll makers in Germany. If there is no mark there is no way to know who made it. The sad part is that many companies, also copied each other so more then one company could make a look alike doll.
I am sorry there is no way to find the maker. The only way you might ever find the maker is if you run across the very same doll being sold or in a book by someone who actually still has the information on the maker.
You are welcome.