shipping per weight with cash on delivery extra charge

Hello to everyone,

I'm trying to configure the shipping mode to my store. But, I'm having a problem. I have been lookin in the forum for a question like that, but I haven't found it. Sorry, please, if it is answered in some place. I will be grateful if someone could help.

I want to configure the shipping mode per weight but it has so many parameters that I'm turning mad.

If the purchase weigh is lower than 3kg, it costs 7,50€. If the purchase weigh is upper than 3kg, it costs 6€ plus 0,50€ per each kg.
But this is not all, if the payment mode is charge on delivery it has an extra charge on the shipping mode that adds 3% on the total purchase bill.

Does anybody thinks if it is possible at least?

Thank you in advance!

Looking for in the forum I found this thread http://www.zen-cart.com/forum/showthread.php?t=29989&highlight=cash+delivery that explains how to configure a % to delivery cash.

But, I'm still trying to configure the shipping module in the case that the purchase weigh is upper than 3kg, it costs 6€ plus 0,50€ per each kg.

Could somenone help, please?

Thanks a lot.