Format Cells
Cell numbers, alignment, or background color can be formatted through the Format Cells dialog. To format a cell, select the cells to be formatted (see Selecting Worksheet Cells), and click the Data | Format | Format Cells command or the 
button. The Format Cells dialog opens.
The Format Cells dialog has three pages: Number, Alignment, and Background.
Number Page
Use the Number page to change the numeric data display in the worksheet.
Alignment Page
Use the Alignment page to set the cell alignment.
Background Page
Use the Background page to set cell background color.
Text String
Number formatting has no effect on a numeric text string (numbers entered as text). A number with an apostrophe in front of it ('8123) is a text string. The apostrophe only shows in the active cell edit box. For example, an ASCII data file might contain the digits "8123" (digits surrounded by quotes), '8123 (digits preceded with an apostrophe), numbers with letters, or numbers with symbols (i.e. a blackslash "\"). These "numbers" are read as text and not as a number. The Transform command can be used to perform a mathematical function, such as ATOI(X), to convert a text string to an integer value. Alternatively, the cell can be converted to numbers with the Text to Number command.
Preserving Cell Format
The only formats that preserve cell-formatting information are Excel or SYLK SLK. ASCII file formats (.CSV, .TXT, .DAT, .BNA, .BLN) do not preserve file format information.