wanna create new channel with layer items

[aijazkanpur]

Hi, Gurus, I have one image with several layers, on one layer i have a circle with drop shadow of same color, i want the elements of this layer only as a new channel including drop shadow (i can't select him via wand or lasso) please help me

 

[X_Rogue_X]

If I'm understanding you, you would like to create a mask using a single layer, including its effects?

If you could post the psd it would be helpful.