Trying to use a golden calf to worship the Lord is NOT using gold for a holy purpose, no matter how many times you write it. That is using gold for an unholy purpose.
The quotes I gave you from Exodus 25 plainly show you what some holy uses of gold would be. Please read those again so that you will see what I mean.
Goodnight.
As my final remark, Aaron's "feasting to the Lord" was a holy intent. But that did not excuse the presence of the molten calf. That the calf was made of gold is completely irrelevant.