Using SE7.2x and C-ISAM both on same data-files

Hi, i have a cisam file collection of an old used customersystem. We want to use it as start-files for a db-application and also continue in using the *.dat/*.idx-files in the application via C-ISAM V5.0. Is this basicly possible? Both usage! Is it possible to build a SE-overhead (systables. etc.) for using the files with SE 7.23? How can i do that, what sys-files are needed? Any tips? Thanks a lot Peter