You can display a Form in datasheet view but I'm not sure it would help you. A solution that comes to my mind is to work with a Form containing the "frozen" data and several subforms (or possibly a tab control) for displaying the other "mobile" columns.
Thanks Sinndho. After your comments that 'You can display a Form in datasheet view'. I did a bit more searching and found that I can do that for a Form via Property Sheet, Format, Default View. Once in Datasheet view, I can freeze fields in the normal way.
Although I have to do the same thing to change out of Datasheet, at least I have a solution for Forms. Thanks for your help.
On Reports though, this does not work. There is no Datasheet option for a report - that I can find.