Invoice tolerance % and value check

Hi,

Happy New year to everyone.

I have to work on invoice tolerance check where i need to check the vendor invoice against a PO value.

This check as per standard SAP can be done either on certain % or certain value for example <= 5% or <= 10GBP

But i would like to have both the checks done.

Example

If i have an invoice whose difference is >5% and the amount difference is less than 10GBP it should not be blocked.

if i have an invoice whose difference is >5% and >10GBP it should be blocked.

how can this be done?

Is there any user exit i can use?

Thanks