how to configure a port for install

[Bob Ababurko]

Hello-

I am trying to figure out how to configure the ports....what I am trying 
to do is add mhash to my system that a new script needs and I have to 
add the --with-mhash=[dir] when I compile php.  Well I installed php 
with the ports and I am hoping to reinstall it with this added.  I have 
tried to add it to the Makefile under the configure options, but I got 
an error that said: "Unassociated shell command".  That obviously is not 
the right way.

Can someone please direct me in doing this, if it is indeed possible.

thanks,
Bob