Text in cell with URL hidden
Use the HYPERLINK() function.

HYPERLINK(url,link-text)

The first parameter is the URL as a string in quotes, the second is the tracking number as a string also in quotes.

From the documentation:


  HYPERLINK
  
  The HYPERLINK function creates a clickable link that opens a webpage
  or new email message.
  
  HYPERLINK(url, link-text) url: A standard universal resource locator.
  url is a string value that must contain a properly formatted universal
  resource locator string.
  
  link-text: An optional string value that specifies the text that
  appears as a clickable link in the cell. If link-text is omitted, url
  is used as link-text.
  
  Examples
  =HYPERLINK(“http://www.apple.com”, “Apple”) creates a link with the text Apple that, when clicked, opens the default web browser to the
  Apple homepage.
  
  =HYPERLINK(“mailto:janedoe@example.com?subject=Quote Request”, “Get Quote”) creates a link with the text Get Quote that, when clicked,
  opens the default email application and addresses a new message to
  janedoe@example.com with the subject line Quote Request.