I have a macro that I use to enter a date from a cell in the worksheet to the left header in the custom header section.

This is the code and it works almost as I want:

ActiveSheet.PageSetup.LeftHeader = Range("CA3").Value
The problem is the date that I plug in to cell CA3 does appear in the header but the font size is 10 and I want to change it to 18 - I also want to make it bold. I've tried various
options which I've been finding on google but none have worked. Here is some code I used which doesn't give me what I want. 

With ActiveSheet.PageSetup
              .LeftHeader = Range("CA3").Value
              .LeftHeader = "18&B&"
         End With
Thanks for any help you can give with proper syntax