How to direct a phytree plot to a particular set of axes?

This question relates to the 'phytree' class, a component of the Bioinformatics Toolbox.

a phytree may be visualized by typing plot(phytree).

However, when trying to specify a particular set of axes (using an axes handle), the program crashes:

plot(handle1,phytree)

??? Error using ==> struct Conversion to struct from double is not possible.

Error in ==> phytree.plot at 98 tr = struct(tr);

modifying the 'phytree' constructor object is not allowed:

set(phytree) ??? Error using ==> phytree.set at 13 Properties in a phylogenetic tree object cannot be manually set. A PHYTREE object must be created by its constructor method PHYTREE or by using one of the functions: PHYTREEREAD, SEQLINKAGE, SEQNEIGHJOIN.

What to do?