The Allowed file types are: brn, doc, dwg, dxf, exe, fla, gif, grab, igs, ini, job, jpg, Lcam, lset, lua, M1s, m3p, m4prof, mcc, mcs, mpg, msi, nc, ods, pcm, pdf, pmc, PNG, png, pst, rar, set, shp, swf, tap, tif, txt, vbs, xls, xml, zip.
You could perhaps use an online converter to change your fcstd files to .dxf.
Tweakie.