You might try this; and Siohando, that is horrible if you have to give it to your Citrix clients. Due to the fact you would have to go to each client running the Windows terminal.
Ok, back to where I was.....
 forgot double quotes in the ftype assignment
assoc.ic="Citrix ICS Client"
ftype "Citrix ICA Client"="%ProgramFiles%\Citrix\ICA Client32\wfica32.exe" %1
I believe the problem when doing this from a command prompt that it will not expand file names to proper NTFS naming conventions without using quotes with a space involved.
Hope this helps,