How to highlight the weeknum column

Select H4:BG4 in your worksheet.

Click on Conditional formatting, and choose New Rule.

Pick "Use a formula to ... format"

Since you are using Weeknum(D1) for current week in B1. You can use that cell for conditional formatting formula.

=H4=$B$1

Apply your format. Done.

EDIT: If you want to highlight entire column.
Select H4:BG60.
And change formula to...
=H$4=$B$1