SDP problems can be solved with PENSDP or PENBMI in TOMLAB. TomSym can also convert the problem to a nonlinear programming problem (NLP) by setting options.type = 'con' before calling ezsolve.
toms rab rac rbc
f = rac;
M = [1 rab rac; rab 1 rbc; rac rbc 1]
con = { positiveSemidefinite(M), ...
-0.2 <= rab <= -0.1, ...
0.4 <= rbc <= 0.5};
x0 = struct('rab',-0.15,'rbc',0.45,'rac',0);
option = struct;
options.type = 'sdp';
solution = ezsolve(f,con,x0,options);