Trying To Combine Multiple Queries Into 1 Main Query

Can anyone help me with how I can accomplish this?

Here is what I currently have:

10 SQL Pass-through queries to update different Date field (Date1, Date2, Date3, etc.) based on the value of the next date field.

This is how each individual query is set up (there are 10 in total)
UPDATE tblApplications SET tblApplications.LastContact = [date1]
WHERE (((tblApplications.Date2) Is Null) AND ((tblApplications.[Date Completed]) Is Null));


Here is what I would like to have: (as 1 query)

UPDATE tblApplications SET tblApplications.LastContact = [date1]
WHERE (((tblApplications.Date2) Is Null) AND ((tblApplications.[Date Completed]) Is Null));

UPDATE tblApplications SET tblApplications.LastContact = [date2]
WHERE (((tblApplications.Date1) Is Not Null) AND ((tblApplications.Date2) Is Not Null) AND ((tblApplications.Date3) Is Null) AND ((tblApplications.[Date Completed]) Is Null));

UPDATE tblApplications SET tblApplications.LastContact = [date3]
WHERE (((tblApplications.[Date Completed]) Is Null) AND ((tblApplications.Date1) Is Not Null) AND ((tblApplications.Date2) Is Not Null) AND ((tblApplications.Date3) Is Not Null) AND ((tblApplications.Date4) Is Null));

Can I somehow combine them together like this or do I have to keep them as 10 seperate queries?