Can admin add items to cart / custom price?

Can the admin add an item to a customers cart? How about for a custom amount?

We sell a monthly service, so the user has a recurring charge. Normally the back office just runs another charge on the users CC each month. We're wondering if theres a way for the admin to add the item to the users cart each month, then we'd generate an email that says something like "you may review and pay your bill online, if you don't pay the amount by X&Y date the charge will be automatically performed". This gives them a convenient online way of seeing pending and past transactions.

We would also need to put a custom-charge item in the cart, for overages they may have incurred in the previous month. So, a pending cart might look like:

1. Renewal charge for February services (the usual $19.99 or whatever).
2. Overage charges for January (non-fixed amount)

Zenners - what's the best way to manage this?

What you are asking is outside the scope of zencart - and probably every other "off-the-shelf" e-commerce system.

You are requiring that an automatic function occurs at a set date/time that writes information to a database.

Building this for zencart may be possible, but is probably going to be governed by CRON JOBS, outside of the framework of the zencart software.

(I would imagine that a completely separate module needs to be written for this - and it's likely to be complicated)

As schoolboy pointed out, if you're looking to do this automatically, it will require custom programming.

If you're planning on doing it manually, take a look at the Admin Tools in the downloads section, specifically Admin login as customer which may help you on your way.

OK, so theres a manual workaround to add predefined items to the cart, but it doesn't address the issue of having an 'arbitrary' charge for eg: overages in the previous month. Any ideas there or back to custom programming?