Then go to http://www.streetmap.co.uk, find the map area of interest which matches the extent of your own image, clicking on the required position, which will then be marked by an orange coloured arrow. Then look for "Click here to convert/measure coordinates" The link will take you to a Grid Conversion Results page. The 'LR' row in the table will provide you with the OS Grid reference of your selected position. Enter the OSGB coordinates into the the appropriate corner of the map above. After pressing the convert button, a fully formatted UI-View32 inf file will be displayed on the right hand side. Just copy and paste this into a .inf file in the UI-View32 map area, along with a map image file of the same name.
Note: You are fitting a 2-dimentional map to the 3-dimentional curvature of the earth. On small maps there is little problem but on larger maps, the deviation becomes more obvious. Thus while the identified corners and its major diagonal will be correct, the more distant areas accumulate a greater degree of error. Adjustments may be required to reduce the errors in the primary area of interest.