using wallet credit for just 50% on total basket value

Hi

I need to just apply the wallet amount for a fixed percentage of basket value (for example 50%) and the rest should be paid by customer.

for example if the customer basket is 300$ and wallet credit is 400$, just 150$ can be deducted from wallet and 150$ rest should be paid by customer.

is it possible or is there any code that i can use to do it?