there are no tutorials for this. you will have to build it yourself.
if i were you i would just build the database out of the spread sheets.
create the recordst on you checkout page (ie at some point after you have collected the location info needed to determine which dhl record(s) to display to the user).
you will have to make this dhl shipping as a shipping option, as well as whatever you other shipping options are. (ie if there are shipping other than dhl offered).
set the selection from the user equal to 2 shipping fields. SHIPPINGNAME and SHIPPINGCOST
in ecart object, set the shipping rule to be equal to session variable SHIPPINGCOST.
on your pages where ever shipping displays to the user, add the display the session SHIPPINGNAME
SOOO lets say you have a package to locationX and weightsY
pull records from the dhl table that are for locationX and weightY
you will have options to display to the user of Express $20, Ground $10, Parcel $5 (or whatever)
your sessions that you create based on thier selection would be
SHIPPINGNAME = DHL Express
SHIPPINGCOST = 20
if I know how your order process flows i can help you better.
and maybe someone else will have a better idea for you.