[ic] Postage charges

[interchange-users@interchange.redhat.com (John Breen)]

Our national postal charges are based on weight, volume and distance.

For instance, a 250g package going 50km might cost $2.75, but the same 
package going 1000km  could cost $3.80.  Now to throw a spanner in the 
works, if the package is too bulky (above a certain size), extra charges 
will apply.  But we can ignore those at present.

What I need to do is to get this scale of charges to work with 
interchange so that it automagically works out the correct postage and 
applies it to accounts.

Does anyone know how I would do this?

Regards

John Breen