ms-access - Combo Box with Rowsource Table/query but also with "select nothing" option

Question

Background:

I am using Ms-Access forms and I have a combo drop-down list that I am coding in VBA

Question:

Is it possible to have a combo based on a query such as: "SELECT tbl.col1 FROM tbl" so you get a dropdown list that is bound...

BUT....

ALSO want to add one more to the list... "None Selected" at the Top.

If some one has ideas, tips or suggestions then please let me know.

Many thanks!

Some Code:

    Me.CboUnallocatedPayments.RowSource = " & _
    "SELECT zTempBankCustomerReceipt.TransType, zTempBankCustomerReceipt.Ref, " & _
    " zTempBankCustomerReceipt.Details,zTempBankCustomerReceipt.EntryDate, " & _
    " zTempBankCustomerReceipt.NetAmt, " & _
    " zTempBankCustomerReceipt.PaidStatus " & _
    " FROM zTempBankCustomerReceipt UNION " & _
    " SELECT 0, "**NOTHING SELECTED**" " & _
    " FROM zTempBankCustomerReceipt" & _
    " WHERE zTempBankCustomerReceipt.TransType = 'SA' " & _
    " AND zTempBankCustomerReceipt.PaidStatus = '0'"