a trouble with predicted binding site of LigandFit

I want to dock a set of ligands to a protein by LigandFit but none of all active site predicted by binding site tool covers fully the position i want to dock in. That's mean the active site is only a small part of the area that i want to dock. I tried expand the binding site but it don't work.

Does LigandFit solve this problem or i need use another program get exactly binding site??

Thank you very much,