This routine fills in id with a ccache
identifier that corresponds to the name in string_name.
It requires that string_name be of
the form type=residual and type is
a type known to the library.
Because of OpenVMS file naming differences, the string_name argument
is formed in a slightly different way than on other platforms.
The equal sign (=) is substituted for the colon (:) to separate
the type from the residual.