Is there a parametric version of fsolve?

[Craig Earls]

I have a multivariable function:

x=foo(r,s,t)

give r and s how can I can find t such that x=0. The order of the
arguments is not important, but I need to vary the other parameters so
hard coding them in and using fsolve is very inconvenient. Ideally what
I would like is something like fsolve, but with extraparameters:

fsolve("foo",r,3,5)

where 3 and 5 get passed throught to foo, and r is varied to find zero.
I am starting to hack fsolve.cc to do this but that looks like a steep
climb for a short project, is ther a better way already extant?
-- 
-----------------------------------------------------------------
Craig P Earls                                 address@hidden
LT US Navy, MIT Ocean Engineering             address@hidden
-----------------------------------------------------------------