Can you browse to that folder path on your hosted server?
I am thinking they placed the imagemagick inside the convert folder
if they did it may be "/usr/local/bin/convert/convert.exe"
if they placed the files in the bin folder instead
the path would be "/usr/local/bin/convert.exe"
in otherwords, wherever they place the files for imagemagick, you should see in the directory list of that folder a file called "convert.exe" (that would be the path you need reference to)
that is about all I know about Imagemagick