parameter and macro driven pivot table filter?

[Ryan Hartnett]

***Originally posted rather sloppily to general questions, but this is more
appropriate here i think.

I am trying to create a pivot table report based on start date and end date
parameters set by the end user. It will produce a report for a given period
of time, by month. Parameters will define the filter in attribute "End
Month-Year" of the pivot table.
I've gotten as far as list boxes that allow defining of 4 names for the the
start and
end dates: BegMo, BegYr, EndMo, EndYr and I have my data attribute "End
Month-Year" (End in this latter case refers to the end dates of contracts or
projects, which is what I am reporting on) in the pivot table. The following
code allows me to select the two start and end dates defined in the pivot
table filter, but it fails to do two things:
a) Remove previously selected values in "End Month-Year" pivot table attribute
and
b) set "End Month-Year" to select all values between "BegMo & BegYr" and
"EndMo & EndYr"

My macro looks like this:

BegMo = Range("E1")
BegYr = Range("F1")
EndMo = Range("G1")
EndYr = Range("H1")

Set pvtTable = Worksheets("Projection Summary").Range("D13").PivotTable

With ActiveSheet.PivotTables("PivotTable1").PivotFields("End Month-Year")
.PivotItems(BegMo & " " & BegYr).Visible = True

ActiveSheet.PivotTables("PivotTable1").PivotFields ("End Month-Year")
.PivotItems(EndMo & " " & EndYr).Visible = True

End With

.....

The good news is I am able to interact with my values in "End Month-Year" by
referencing concatenated "BegMo" and "BegYr", so at least that works.

Help with this?

Thanks,
Ryan