Add new "tax type" for Finance industry - can only claim 75% of GST on expenses

Hi

I am hoping the response to adding a new GST type for the WET question asked earlier today will help.  Just in case it doesn't..........

I would like to add a new GST code for 7.5% (75% of 10% GSTclaimable by my client in the finance industry) so that the expenses that are posted through do not need to be manually adjusted from the standard 10% as they are recorded.  

Is this possible?  Or will I have to do this manually every time??  The manual option would be time-consuming and potentially prone to data entry errors.

Thanks in advance.