The matching contribution can be deposited into any SIMPLE IRA (assuming that a DFI is not being used). A bank would probably establish the account.
If the employee is unwilling to establish account or can not be located, the employer can establish account on employee's behalf.
If contribution not made, then the Simple is not a Simple for the year and all 2004 contributions are excesses (generally reported in Box 1 of Form 1099 (for 2004), or not deducted if SE). To avaid the possibility of double taxation, the excess should be removed before due date of individual's federal income tax return.
Hope this helps.