Create a form and put a text box on it that will list the customer number. Perhaps using a combobox. Then create a command button and put VBA code behind it that says run the report but only show the information for the listed customer.
Here is code that I have used for a similar situation
Code:
Private Sub Command28_Click()
On Error GoTo Err_Command28_Click
Dim stDocName As String
stDocName = "Submission"
'DoCmd.OpenReport stDocName, acNormal, , "[ID] = Forms!frmClients!ID"
DoCmd.OpenReport stDocName, acViewPreview, , "[ID]=Forms!frmClients!ID"
Exit_Command28_Click:
Exit Sub
Err_Command28_Click:
MsgBox Err.Description
Resume Exit_Command28_Click
End Sub
You will have to change the forms and field names appropriately, but htis should give you a step in the right direction.
Alan