If you are copying the formula from a single cell, the fastest way is to copy the text from the formula bar. That is, click on the cell to get the formula displayed in the formula area, then drag the highlight over the text there with the mouse and press ctrl-c (or right mouse click and select Copy). Go to the cell where you want the formula, and paste the formula into the formula bar.

If you are trying to copy the formulas from the whole sheet, use the following process:

• Use Edit | Replace and change all occurences of = to '=
• Select the whole sheet by clicking in the top left hand corner
• Copy the cells
• Change to the sheet where you want the formulas
• Paste the cells
• Use Edit | Replace to change all occurrences on the sheet of '= to =
  

Does that help?