Create and/or modify radial dimension style

Maybe it's just a case of the Monday's or maybe my heads still at the beach,
but... how can I create a Radial dimension style without having to go
through the DimStyle dialog??

I have a program that creates dimstyles based on the ltscale (both linear
and radial dim styles). The program reads an external file to set the dim
variables. It creates the linear dim style (the parent) then makes a copy
of that style as a radial dim style (the child). I would like to be able to
change the prefix and suffix of the child dim style without having to go
through the dialog box.

When the program is done, I end up with MYDIMSTYLE (parent) and MYDIMSTYLE$4
(child).

Thanks in advance!