Comparing the two languages, I would submit that your migration/conversion will involve not only programming code changes but also FOCUS-to-SAS environment changes, such that an automated process would not be practical nor effective.
So, here are some thoughts:
1) develop a high-level migration plan and get mgmt written approval to start an exploratory / discovery effort for the migration (CYA).
2) solicit input from both production and adhoc FOCUS users to best identify and characterize your audience - identify features, functions, components, used today and what they "could use" with SAS, to improve the sell-job.
3) develop a list of application programs to convert and rank them in priority and complexity; also develop a list of reference databases / sources which will also need to be considered with the conversion effort.
4) develop a training requirements summary and assess the cost for addressing the learning-curve as best as possible.
5) determine what OS platform(s) best suits your user base.
6) revise #1 above and go back to mgmt for written approval again (further CYA).
7) develop a detailed migration plan which includes code and database migration (with robust testing), parallel-operation for some time-period, training, and offer some time-period to phase out FOCUS, if that is intended.
8) ...more related tasks...