Figure, Fret, and String notation

[bannersite]

Good Morning,

I'm new to the software and I'm looking to add String numbers to the following:

\relative c {
    \clef bass

c^3_2 d^5_4
        %{ string change %}
e^2_1 f^3_2 g^5_4
        %{ string change %}
a^2_1 b^4_3 c^5_4

}

I thought I had a solution by using rightHandFigure forced down. However I ran into trouble when I tried to \override StrokeFigure #'digit-names to numbers

Is this the best approach? Would there be a more effective way to get upper and lower numerical referance with the addition of string numbers?

Thanks

Scott