One of the structures is as follows:

Format of ACEOpenArchiveData structure:
struct ACEOpenArchiveData
{
char *ArcName;
UINT OpenMode;
UINT OpenResult;
UINT Flags;
UINT Host;
char AV[51];
char *CmtBuf;
UINT CmtBufSize;
UINT CmtSize;
UINT CmtState;
int (*ChangeVolProc)(char *ArcName,int Mode);
int (*ProcessDataProc)(unsigned char *Addr,int Size);
};

The function call is:
HANDLE ACEOpenArchive(struct ACEOpenArchiveData *ArchiveData);

Johan.