You can do this with a couple of extra fields.
First create a text field with the maximum length you desire called
URL_Name__c or similar.
Then create a new formula field that returns a text value. Inside that the formula uses the
HYPERLINK function to combine the two other fields into a shorter link.
HYPERLINK(Website, IF(ISBLANK(URL_Name__c), Website, URL_Name__c), 'blank')
Note that with this basic formula, if the
Website field does not contain
http:// then the link will try to link to an internal location, so that should always be specified. If you want to make the formula more tolerant of this, then you can also check for the presence of "http" at the start of the URL:
IF(LEFT(Website, 4) == 'http', Website, 'http://' + Website),
IF(ISBLANK(URL_Name__c), Website, URL_Name__c),