Yet another shipping question, sorry!

I have been given the following info for shipping and wondered if this was at all possible with the shipping settings:


FREE DELIVERY UP TO 30 KILOS 48 TO 72 HOUR SERVICE
Free delivery is applicable to on line orders over the value of £50.00 + vat and up to 30 kilos in weight for the first parcel only. Then £5.50 + vat per parcel there after.


UP TO 30 KILOS EXPRESS DELIVERY SERVICE
£6.50 + vat for this service for the first parcel up to 30 kilos, and £4.50 + vat for every parcel up to 30 kilos thereafter.

UK MAINLAND FOR LARGER ITEMS OVER 30 KILOS
24 hour service up to 70 kilos is £20.00 + vat, then a charge of £0.20 per kilo thereafter.
48 hour service up to 60 kilos is £15.00 + vat, then a charge of £0.20 per kilo thereafter.
72 hour service up to 70 kilos is £15.00 + vat, then a charge of £0.20 per kilo thereafter.



Is it at all possible to trigger free shipping when the cart is over £50 and under 30 kilos? Do I have to amend pages somewhere to achieve this?

Sorry for the repeated and different questions about shipping from me... I must be getting to the end of them now!!

Thanks.

Mat