With a reference star listing, JIMSAIP can construct a reference chart that can be correlated with your images to produce a calibrated image from which accurate positions may be read. Actually, JIMSAIP doesn't care where the star listing comes from, but we have adopted the output format available from Guide 4.0 from Project Pluto and/or the format from the WEB site of the Space Telescope Science Institute. If other sources (even manual input) can reproduce either of these formats, JIMSAIP can read it and produce the reference map.
Using Guide 4.0, the process is almost identical to that of producing a finder chart for use at the telescope. I will illustrate with my procedure and you can adapt as needed. As my CCD field of view is well under one degree, I usually produce a finder chart with a one degree width (level 8 in Guide 4.0) with my target in the center. JIMSAIP requires the RA and DEC data to be in decimal degrees, so I adjust the RA/DEC display to show decimal degrees (from the Guide main menu, select Settings, and then RA/DEC display which toggles the display among several choices).
Press F10 and you will be asked to input a limiting magnitude. Put in 20 and press {Enter}. You will then be shown a listing (possibly multipage). Be sure to double check that the RA and DECs are in decimal degrees. One of the buttons at the bottom includes Save to File. Select this and where asked, input the file name (including directory path). I usually use a name derived from the object, but the extension MUST be .G11 for JIMSAIP to find it. For example, if I have a map for the minor planet 1986 SS4, I would input for the file name \ccdimage\961208\1986SS4.G11. You can, of course, use any naming convention you want (just be sure to use the extension .G11) and put the file where you will but it will be more convenient later if the .G?? files are in the same directory as the image files.
The process for getting the needed data file from the Space Telescope Institute is a little more simple - if you have WEB access. Go to their WEB site and download the request form. Make a copy of it for keeping on your hard drive. To use, just fill in the blanks with the center of the desired field and select sufficient field width to cover your image. When the data file downloads, you must save it to your hard disk with whatever name you chose, but this time, the extension MUST be .G12 (because the file format is different from Project Pluto - JIMSAIP can tell them apart if the extensions are correct).