Accessing binary file with custom format to get metadata?



I have been looking into creating a metadata agent for plex but cant find any info or examples(code) on if its possible to access a custom formatted file with metadata.

For example, if the first 4-bytes(dword) of the file indicate the offset from the start of the file to the title string within the file, how do i create a pointer to that string? The file starts with a set of 4-byte(dword) offset(s) that point to a specific string followed by the strings themselfs.

Also, is bit manipulation on a variable(byte/word/dword) possible? (like shifting and masking bits)

If its not possible to do this in the plex plug-in code, would it perhaps be possible to create a library and import its functions?