Recalculate Total field

Hello,

We are using Quote Management in Cloud for Customer and at the moment we are adjusting the lay out form in Adobe Life Cycle Designer.

As we have no external pricing with SAP ERP I added a custom field (VAT) in C4C and I connect this in LCD via bindings.

Now, I want to recalculate the standard total field by adding the VAT.

I noticed there is a script editor window but i'm not able to (or I don't know) how to properly write the script.

Is it possible to recalculate the standard total field price ?

Thanks!