Populate Array then Display in MsgBox

I need to populate an array then put the array info into a MsgBox.

This is what I have so far, but it's got problems. I need help getting this to work.

Dim strExpired() As Long
Dim k As Variant
Dim a As Integer
Dim c As String

a = 0
For Each eCell In Range("Expiration_Dates")
    If eCell.Value < ((Range("Current_Week") + 0.417) + Range("Days_Between_Orders")) Then
        strExpired(a) = eCell.Value
        a = a + 1
    End If
Next
a = 0
For Each k In strExpired
    c = "c" & Chr(10) & strExpired(a)
    a = a + 1
Next
MsgBox c, vbOKOnly