File format for Ansys and Nastran output in Mechanica

I need to output a mesh file to use in Ricardo Valdyn.  The file formats Ricardo list as being supported are:

Ansys: ASCII - .cbd  / Binary - .rst

MSC-Nastran : ASCII - .dat / Binary -  .f12

I can output a Ansys and Nastran file via FEM analysis, but I cannot control the file format.  The Ansys file is exported in .ans and the Nastran file is exported in .nas formats respectively.  How do I output the required file format?

Thanks,

Dan