How do I frozen a certain part of a worksheet?

[officeboy09]

Hi,


I'd like to frozen or lock up some particular rows on a worksheet so that wherever I scroll on that worksheet, the frozen rows remain in their positions.
I remember it should be a selectable feature under the tools menu, but now I forgot excatly how it was done before.
Does this function also apply to locking up a specific area confined by a certain number of row and column?