need help with bash -c <command> with cygpath

[Jay]

When i run
>cygpath -a '\\uncpath\mydrive$'
//uncpath/mydrive$

Which is the expected behaivor.

When i run
>bash -i -c "cygpath -a '\\uncpath\mydrive$'"
/C/uncpath/mydrive$

Which is not what i want.  I'm trying to pass in the unc path from windows, so
it needs converted.

Why do i get different results depending on how it is called? 

Thanks in advance.

Jay.