Changing Default 'Look In' Directory

When trying to save a new file under "Save As", is there a way to change the default directory to a different directory permanently? If so, how do you go about it? Even in Outlook 98, is there a way to have a shortcut button on the toolbar in the "Insert" window to the directory I want to pull my files from. For example, (in Outlook and Windows 9x itself) I create a new message and then want to insert a file into the email; is there a way to have the default directory changed to the directoryI prefer permanently or even have a button to click on to pull the file from?