Fixed Interest Rate vs Reducing/Diminishing Interest Rate sheet or calculator

[slicksilver79]

Hello all

I was hoping if somebody has a sheet which can covert fixed interest % to reducing interest % and vice versa in excel. I'm not very such about the math involved here as well. Is anybody of you into finance ? If yes any help would be greatly appreciated.

Thanks!

[slicksilver79]

any idea anyone? bump