Load all pages using L_LoadBitmapList
If you wish to load only one of the pages, set the page number in an instance of LOADFILEOPTION when calling a loading function.

Multi-page files can be loaded more quickly using two mechanisms, as follows:

TIFF files can use the IFD (offset of each page). For more information about loading and saving large TIFF files more quickly, refer to Loading and Saving Large TIFF/BigTIFF Files.
Some file formats other than TIFF files can use a filter data mechanism. Retrieve the filter data by calling L_FileInfo with the FILEINFO_USEFILTERDATA flag. If the filter supports this mechanism, the filter data is returned by filling the pFilterData, uFilterDataSize and nFilter members of the FILEINFO structure. You then pass the filter data through LOADFILEOPTION structures to the load or convert functions and then free them with L_FreeFilterData when they are not needed anymore. See the Using Filter Data to Speed up Loading Large Files topic for more information.