at the right vs. on the right

[renetta]

Hello,

can I use "at the right/at the left" alternatively to "on the right/ on the left"?

e.g. "At the right of the window there is a picture"

Thank you

[phanshishui]

Hello,

can I use "at the right/at the left" alternatively to "on the right/ on the left"?

e.g. "At the right of the window there is a picture"

Thank you

I think it is not right if we use " At the right/left"
On the right/left is a fixed phrase.
But i don't know we can use "on the right/left" in normal case or not
I don't find the rule here