Find and use multiple occurences of a string in a string

I recently started using Python and wrote some simple scripts Now I have this question:

I have this string:

mystring = 'AAAABBAAABBAAAACCAAAACCAAAA'

and I have these following strings:

String_A = BB
String_B = CC

I would like to get all possible combinations of strings starting with String_A and ending with String_B (kind of vague so below is the desired output)

output: 
BBAAABBAAAACCAAACC
BBAAABBAAAACC
BBAAACCAAAACC
BBAAACC

I am able to count the number of occurences of String_A and String_B in mystring using

mystring.count()

And I am able to print out one specific output (the one with the first occurence of String_A and the first occurence of String_B), by doing the following:

if String_A in mystring:
    String_B_End = mystring.index(String_B) + len(String_B)
    output = mystring[mystring.index(String_A); String_B_End]
    print(output)

this works perfect but only gives me the following output:

BBAAABBAAAACC

How can I get all the specified output strings from mystring? thanx in advance!