Assistance required with which formula to use to create a Master sheet referencing other workbooks

[Buttontoes]

Hello everybody I am seeking so advice on how do collate a summary for the financial year of the invoice date, hours worked, the associated codes (possibly 4 per invoice), and total dollar value.


Thanks in advance


I generate weekly invoices with the (day In Column A), (the date in column B) (hours worked In Column C), (Services Description in column D, "from a drop-down list"), (the hourly rate in column E, "=VLOOKUP(D17,VRate,2,0)"), and (total in column F)

Refer details below:
[TABLE="width: 796"]
<colgroup><col><col><col><col><col><col></colgroup><tbody>[TR]
[TD]DAY[/TD]
[TD]DATE[/TD]
[TD]HOURS[/TD]
[TD]DESCRIPTION[/TD]
[TD]HOURLY RATE[/TD]
[TD]TOTAL[/TD]
[/TR]
[TR]
[TD]Sunday[/TD]
[TD]27-Jan-19[/TD]
[TD]2[/TD]
[TD]Care Assistance (Sunday) 01_014_0107_1_1[/TD]
[TD]$85.14[/TD]
[TD="align: right"]$170.28[/TD]
[/TR]
[TR]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD]Community Participation 04_104_0125_6_1[/TD]
[TD]$48.14[/TD]
[TD="align: right"]$0.00[/TD]
[/TR]
[TR]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD]Personal Training 12_029_0126_3_3[/TD]
[TD]$55.72[/TD]
[TD="align: right"]$0.00[/TD]
[/TR]
[TR]
[TD]Monday[/TD]
[TD]28-Jan-19[/TD]
[TD]3[/TD]
[TD]Public Holiday 01_005_0104_1_1[/TD]
[TD]$107.00[/TD]
[TD="align: right"]$321.00[/TD]
[/TR]
[TR]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD]Community Participation 04_104_0125_6_1[/TD]
[TD]$48.14[/TD]
[TD="align: right"]$0.00[/TD]
[/TR]
[TR]
[TD] [/TD]
[TD] [/TD]
[TD] [/TD]
[TD]Personal Training 12_029_0126_3_3[/TD]
[TD]$55.72[/TD]
[TD="align: right"]$0.00[/TD]
[/TR]
[TR]
[TD]Tuesday[/TD]
[TD]29-Jan-19[/TD]
[TD]2[/TD]
[TD]Care Assistance (Evening) 01_015_0107_1_1[/TD]
[TD]$52.17[/TD]
[TD="align: right"]$104.34[/TD]
[/TR]
</tbody>[/TABLE]


All of these invoices are stored in the SAME DIRECTORY with CONSECUTIVE NUMBERS for example
Casey_Brown_Invoice_201
Casey_Brown_Invoice_202
Casey_Brown_Invoice_203



What I am trying to do is get a Master Sheet Summary of all the invoices in the directory.


Currently, I can achieve this in the worksheet by using


"=SUMIFS(C17:C37,D17:D37,"=Care Assistance (Weekday) 01_011_0107_1_1")"



The invoice "Date" in cell F3 every time
The total number of "Hours", >0 spent on each Service Description
The "Service Description" cell could be variable
The "Total Dollar Value" cell could be variable


I hope this is not too complicated I am just trying to provide as much information as possible. Thanks again in advance.
Peter