Converting *.dta files to dbase,paradox or interbase???

I have customers that use Billant Accounting (for DOS) and TAZ inventory
system but would like to access there database with delphi 2/3 because of
the limitations the above software holds.

Can anybody advise me on how to do that or what software or OBDC drivers i
need to access these files in either DBase, Paradox or Interbase.

My mailbox is

Johannesburg, South Africa