Trying to figure out if (and how) this can be done...

I sell product and gift certificates. The GCs are printed in hardcopy (not via e-mail). I currently use Table Rates for shipping product and this is based on total price of the product purchased (ie: <$25 is $8.25, $25-$50 is $10.50, etc). However I need to have custom shipping pricing if there are GiftCerts in the cart order as follows:

- If the only type of item is a Gift Cert (any Qty of them for any total value), I want to only charge $0.41 (which covers standard first class mail postage).

- If there is actual product in the order in addition to Gift Certs, then the shipping rate is based on the product total cost (not including GC value) and uses Table Rate shipping only - does not add $0.41 (since the hardcopy GC will be included in the shipping package).

Can this be done using the built-in admin tools, does it require a contributed add-on module, or must some .php file be hacked to do this?

Thanks in advance!