How do I reference functions from another template?

Lets say I have a template, dir1/dir2/dir3/foo.tmpl:

#def FooFunct($param1, $param2):
  Stuff here
#end def

and another template where I want to call FooFunct, dir1/base.tmpl:

#include "dir1/dir2/dir3/foo.tmpl"
#* Want to call $FooFunct("1", "2") *#

I assume I need to import foo in some way but don't know where it
lives (I have tried from dir1.dir2.dir3 import foo already ;).  Is
there a way of doing this without first compiling foo.tmpl?

Thanks,
Saul

------------------------------------------------------------------------------
The NEW KODAK i700 Series Scanners deliver under ANY circumstances! Your
production scanning environment may not be a perfect world - but thanks to
Kodak, there's a perfect scanner to get the job done! With the NEW KODAK i700
Series Scanner you'll get full speed at 300 dpi even with all image 
processing features enabled. http://p.sf.net/sfu/kodak-com