Michael,
I've created a working model based on the specifics you've described.
This model uses Excel's "database extraction" function to "filter" out and extract the required data to a separate sheet.
Because Excel's database functions are built-in custom functions, they are written in the "C" language and are therefore "lightning fast" in comparison to using strictly VBA.
If you'd prefer, I can email you the file. Just email me, and I'll send the file via return email.
If you want to set the file up on your own, here's the code... (Copy it into a Module)
Sub Combine_Data()
'combines zipcode data from all sheets into sheet
'named "AllData".
Application.ScreenUpdating = False
cnt = ThisWorkbook.Worksheets.Count - 3
n = 0
For n = 1 To cnt
Sheets

.Select
Set_Data
Extract_Data
Set_ExtData
Copy_ExtData
Next n
Application.Goto Reference:="R1C1"
Application.ScreenUpdating = True
End Sub
Sub Set_Data()
'sets the input database range name ("data"

Application.Goto Reference:="R1C1"
Selection.Insert Shift:=xlDown
ActiveCell.Value = "Z_C"
FirstCell = ActiveCell.Address
LastCell = [A65536].End(xlUp).Offset(1, 0).Address
rng = FirstCell & ":" & LastCell
Range(rng).Name = "data"
Range("data"

.NumberFormat = "@"
Application.Goto Reference:="R1C1"
End Sub
Sub Extract_Data()
'extracts zip numbers to Extraction sheet
Application.ScreenUpdating = False
Range("data"

.AdvancedFilter Action:=xlFilterCopy, _
CriteriaRange:="crit", _
CopyToRange:=Range("ext"

, _
Unique:=False
End Sub
Sub Set_ExtData()
'sets the range name "extdata" for extracted data
Worksheets("Extraction"

.Select
Application.Goto Reference:="R2C1"
FirstCell = ActiveCell.Address
LastCell = [A65536].End(xlUp).Offset(1, 0).Address
rng = FirstCell & ":" & LastCell
Range(rng).Name = "extdata"
End Sub
Sub Copy_ExtData()
'copies range named "extdata" to "AllData" sheet
Worksheets("AllData"

.Select
LastCell = [A65536].End(xlUp).Offset(1, 0).Address
Range(LastCell).Select
Range("extdata"

.Copy
ActiveSheet.Paste
End Sub
=============
IMPORTANT:
=============
Before running the routine "Combine_Data", you'll need to perform the following steps...
1) Insert 3 sheets to the right of your 76 sheets.
2) Name these sheets: Extraction, AllData, and Criteria.
3) In the Extraction sheet, enter "Z_C" in cell A1.
4) Assign the range name "ext" to cell A1.
5) In the AllData sheet, enter "Z_C" in cell A1.
6) In the Criteria sheet, enter the label "crit" in cell A4.
7) In cell B5, enter this formula... =LEN(z_c)=5
8) Highlight B4:B5, and assign the range name "crit".
9) On the Criteria sheet, add a macro button, name it "Combine Data", and attach the routine "Combine_Data".
That's all. Clicking the button will of course merge your data.
Note: While there are different ways to create range names, the method I always recommend is...
a) Highlight the cell or range-of-cells
b) Hold down <Control> and hit <F3>
c) Type the name
d) Hit <Enter>
I hope this works to your satisfaction. Please advise as to how you make out. Don't hesitate to ask for the file if you prefer.
Regards, ...Dale Watson
HOME: nd.watson@shaw.ca
WORK: dwatson@bsi.gov.mb.ca