Multi-Line Cells

I'm trying to process lots of data from purchased mailing lists for my company.  Some of these lists are in excel with multiple lines of data within a cell.  I'm loading a TAdvStringGrid (current version) from excel spreadsheets.  How do I read multiple lines from these cells.  I'd expect to use something like a TStringList, but am unsure as to how to proceed.  The manual doesn't have an suggestions for having a program read the content of these cells.  And, is there a way to tell when a cell has multiple lines?

Grid->Cell[x][y]->Lines->AddStrings(myTStringList);  ??

A cell is accessed as a string. If it contains multiple lines, that means it will return a string with linebreaks.