I've got it figured out now.

I did end up having to add open brackets but I separated the path and the filename with &. it seems to work just fine now. 

Dim Loc As String
Loc = "J:\CUSTOMER SERVICE\Group Service Center\!!!GCS Management\Monthly Roll-Up Reports\Lethbridge\1 - Statistics\Telephonic Stats\" & "[telephonic Errors " & Format(Sheet10.Calendar1.Value, "YYYY") & ".xls]"
Selection.offset(0, 3).FormulaR1C1 = "=SUMPRODUCT(--('" & Loc & "Sheet1'!R2C1:R3000C1=RC[-2])*('" & Loc & "Sheet1'!R2C5:R3000C5=RC[-3]),'" & Loc & "Sheet1'!R2C2:R3000C2)"
Selection.offset(0, 4).FormulaR1C1 = "=SUMPRODUCT(--('" & Loc & "Sheet1'!R2C1:R3000C1=RC[-3])*('" & Loc & "Sheet1'!R2C5:R3000C5=RC[-4]),'" & Loc & "Sheet1'!R2C3:R3000C3)"
Selection.offset(0, 5).FormulaR1C1 = "=SUMPRODUCT(--('" & Loc & "Sheet1'!R2C1:R3000C1=RC[-4])*('" & Loc & "Sheet1'!R2C5:R3000C5=RC[-5]),'" & Loc & "Sheet1'!R2C4:R3000C4)"