Dim s1 As String, s2 As String, s3 As String, s4 As String
Dim s5 As String, cnn As ADODB.Connection, cat As ADOX.Catalog
Dim tabx As ADOX.Table
s1 = "Driver={Microsoft Excel Driver (*.xls)};" 'courtesy Carl Prothem
s2 = "DriverId=790;"
s3 = "Dbq=f:\accesss\northwind\northwind.xls;"
s4 = "DefaultDir=f:\accesss\northwind;"
s5 = s1 & s2 & s3 & s4
Set cnn = New ADODB.Connection
cnn.Open s5
Set cat = New ADOX.Catalog
cat.ActiveConnection = cnn
cat.Tables.Delete "Sheet3$"   'error 3251

You can use this instead if the user has Excel. If not, consider  text files.
I haven't played with it but  Carl's site has the connection string for text
files.

Dim v1 As Variant, j As Integer
Dim app As excel.Application, wrkbk As excel.Workbook
Dim wrksht As excel.Worksheet
Set app = New excel.Application
app.DisplayAlerts = False
Set wrkbk = app.Workbooks.Open("f:\accesss\northwind\northwind")
wrkbk.Worksheets("Sheet3").Delete
wrkbk.Close True
Set wrkbk = Nothing
app.Quit
Set app = Nothing

Bobby's right that the ADO libraries don't allow you to delete any
"physical" objects from Excel -- neither a worksheet nor a single row.  You
have to use Automation if your application needs this ability.

Here are some articles on Excel and ADO:

Using ADO with Excel: Resources and Known Issues
October 18, 2001

Microsoft Knowledge Base articles can be found at:
http://search.support.microsoft.com/kb/c.asp
Choose to search by "specific article ID number"
Enter the article number including the "Q"

.Net versions of some of these articles are coming soon!

General
-------
Q257819 HOWTO: Use ADO with Excel Data from Visual Basic or VBA
Q303814 HOWTO: Use ADOX with Excel Data from Visual Basic or VBA
Q278973 SAMPLE: ExcelADO Shows How to Read/Write Data in Excel Workbooks
Q195951 HOWTO: Query and Update Excel Data Using ADO From ASP
Q306397 INFO: Use Excel with SQL Server Linked Servers and Distributed
Queries

Transferring Data into Excel
----------------------------
Q247412 INFO: Methods for Transferring Data to Excel from Visual Basic
Q295646 HOWTO: Transfer Data from ADO Data Source to Excel with ADO
Q246335 HOWTO: Transfer Data from ADO Recordset to Excel with Automation

Related How-To Subjects
-----------------------
Q244761 XL2000: How to Use ADO to Return Data to a ListBox or ComboBox
Q285891 HOWTO: Use VB or ASP to Create an XML Spreadsheet for Excel 2002
Q276488 HOWTO: Use ADODB.Stream to Read Binary Files to the Browser
Q199841 HOWTO: Display ASP Results Using Excel in IE with MIME Types
Q278976 HOWTO: Transform Excel XML Spreadsheet for Server-Side Use

Known Issues
------------
Q211378 XL2000: 'Could Not Decrypt File' Error with Password-Protected File
Q246167 PRB: Collating Sequence Error Opening XLS as ADO Recordset
Q288343 BUG: Excel ODBC Driver Disregards FirstRowHasNames/HDR Setting
Q281517 PRB: Transfer of Data from Jet 4.0 OLEDB Source Fails w/ Error (DTS
to Excel)
Q293828 BUG: Excel File Size Grows When You Edit ADO Recordset
Q300948 BUG: Incorrect TABLE_TYPE Is Returned for Excel Worksheets

Known Issues working within Excel
---------------------------------
Q263498 BUG: Run-Time Error 5 Using Add Method of QueryTables Collection
Q215154 XL2000: Excel does not support OLE DB Data Links
Q228633 OFF2000: "Catastrophic Failure" Error Running Samples.xls Macro
Q291199 XL2002: "Invalid Use of New Keyword" Error Using ADODB Library
Q225059 XL2000: "Invalid Use of New Keyword" Error Using ADODB Library

This posting is provided AS IS with no warranties, and confers no rights.