Actually in order to emulate a C#m13, it should be notated as a EMaj9#11/C#. The EMaj9/C# don't have the 13th.
If you don't need the 11th in the chord, then it could be notated EMaj7#11/C#.
However, it would be better if the m13 chord type be added in the library. It's a pretty common chord used in jazz music!