Date subtraction as part of a condition when summing group on expression

Hi Experts:

I am pretty new to SSRS but I need to do the following:

I have a Group on "Warehouse" the column contains this expression, which is working:

=Microsoft.VisualBasic.Interaction.Iif(Fields!CurrentHodDT.Value = Fields!OriginalHodDT.Value, Sum(Fields!CurrentQTY.Value), 0)

I need three totals:

Records that are "ontime", "Late by 1 to 2 weeks (between 7 and 14 days)", and a group total on 3 weeks plus (21+ days)

Working with one at a time, I have this for "Late by 1 to 2 weeks"

=Switch((Fields!CurrentHodDT.Value =< Fields!CurrentHodDT.Value -14) AND (Fields!CurrentHodDT.Value => Fields!CurrentHodDT.Value - 7), Sum(Fields!CurrentQTY.Value),0)

This returns an error: The Value expression for the textrun ‘Textbox287.Paragraphs[0].TextRuns[0]’ contains an error: [BC30201] Expression expected

I have seen lots of articles on Google but nothing has helped me so far.

Any advise would be greatly appreciated.

Thanks

Todd