The square symbol can be removed using a VB fucntion as part of an update query
in your function yu will need to find if the specified characters exist (instr is your friend), and then replace() such occurances. have a look at the helpfile for string functions.
I forget which but the symbols your are looing for are Chr$(10) and / or chr$(13)
failing that you could test in your function to find non standard characters and then replace those (non standard meaning anything outside the alphanumeric & punctuation characters) - search for the chr() & Asc() fnctions for more details
I forget if you can search for the unprntable character using like "*" & chr$(x) & "*", however if evry record or virtually every record has this in then just select all in the query.