Are the records parsing correctly into discrete fields, or are the
records all text that somehow wrap onto the next line? How the data
starts out and how it's showing up vs. how you want it to show up makes
a difference in how you address the problem.

The software that is creating the file for export *may* be including
line feed characters in the output; if the line feeds were not there
the second line would not be an issue. If this might be the case and
if you're feeling adventureous, make a backup of the export, open it
using MS Word, and search for a special character, ^l (that's the
caret symbol, shift 6, and a lower case L). If you see those within a
record, do a search and replace and replace with nothing, then save and
import to Excel. If the MS Word search yields nothing, try other
special characters in the search window (click the More button and the
Special button to reveal all your options).

Another possibility, again depending on the nature of the data: import
to Access rather than Excel.