If you run gdalinfo you'll notise that GDAL does recognize .jpgw as a World file.
gdalinfo QAP27863800.JPG
Driver: JPEG/JPEG JFIF
Files: QAP27863800.JPG
QAP27863800.jpgw
Size is 3800, 4000
GeoTransform =
15923663.02324857, 0.6464472699464198, 0.004029513396384988
-1123438.005344422, 0.004072074029169209, -0.6506963195161204
Metadata:
EXIF_BitsPerSample=8
EXIF_ColorSpace=65535
EXIF_Compression=1
EXIF_DateTime=2010:02:18 13:09:37
EXIF_Orientation=1
EXIF_PhotometricInterpretation=1
EXIF_PixelXDimension=3800
EXIF_PixelYDimension=4000
EXIF_ResolutionUnit=3
EXIF_SamplesPerPixel=1
EXIF_Software=Adobe Photoshop CS3 Windows
EXIF_XResolution=(666.667)
EXIF_YResolution=(666.667)
Corner Coordinates:
Upper Left (15923663.023,-1123438.005)
Lower Left (15923679.141,-1126040.791)
Upper Right (15926119.523,-1123422.531)
Lower Right (15926135.641,-1126025.317)
Center (15924899.332,-1124731.661)
Band 1 Block=3800x1 Type=Byte, ColorInterp=Gray
Overviews: 1900x2000, 950x1000, 475x500
Image Structure Metadata:
COMPRESSION=JPEG
WGS84 coordinates of the location are about 143.03°E, -10.07°N. What remains is to find the right code for the coordinate reference system that is used in the .jpgw file.