The conversion of the project was successful.

The new directory structure is as follows:

d:/psd_data/flyback/1
    flyback.opj
    FLYBACK.dsn
d:/psd_data/flyback/1/flyback-PSpiceFiles
    FLYBACK.err
    FLYBACK.olb
d:/psd_data/flyback/1/flyback-PSpiceFiles/FLYBACK
    FLYBACK-default.mrk
