How does P&L comes in?
Anyway, see the pic below, esp the pip cost column. Not sure if it is helpful.
You mentioned the 3 pairs GBP/JPY, EUR/JPY and EUR/GBP.
So if you see GBP/JPY, each pip would be worth 0.9 of what you see.
And if you see EUR/JPY, each pip would be worth 0.9 of what you see.
And as for EUR/GBP, each pip would be worth 1.76 of what you see.
So in excel, you can just add an extra column e.g. "Actual GBP/JPY value" with value as =GBP/JPY_Col * 0.9.
PS.: The rates were captured at this point of writing. The numbers are just a rough gauge but should not vary too much too soon.