Hi Iris,
Access text fields can't store differently formatted characters. One way
round this is to format the controls that display the field in a font
that includes superscript characters.
Most ordinary fonts include superscript 1,2 and 3; some Unicode fonts
such as Lucida Sans Unicode include all the numerals 0..9.
Otherwise, it's possible to store text in HTML or RTF format in a memo
field and display this in a browser or rich text control - but it's not
simple.