If you have a Florida matter that needs to be tended to, you have to deal with it in Florida or hire a lawyer in Florida to do it for you.
However, you may not be eligible. Florida will only allow you to seal your record if it is your first and only sealed offense AND it didn't result in a conviction or was an adjudication withheld.
(1) Petition to expunge a criminal history record.__Each petition to a court to expunge a criminal history record is complete only when accompanied by:
(a) A certificate of eligibility for expunction issued by the department pursuant to subsection (2).
(b) The petitioner's sworn statement attesting that the petitioner:
1. Has never, prior to the date on which the petition is filed, been adjudicated guilty of a criminal offense or comparable ordinance violation or adjudicated delinquent for committing a felony or a misdemeanor specified in s. 943.051(3)(b).
2. Has not been adjudicated guilty of, or adjudicated delinquent for committing, any of the acts stemming from the arrest or alleged criminal activity to which the petition pertains.
3. Has never secured a prior sealing or expunction of a criminal history record under this section, former s. 893.14, former s. 901.33, or former s. 943.058, or from any jurisdiction outside the state.
4. Is eligible for such an expunction to the best of his or her knowledge or belief and does not have any other petition to expunge or any petition to seal pending before any court.
If your matter was not dismissed or a deferred adjudication, the only remedy you would have to lessen some of the employer discrimination you are subjected to would be to get a pardon granted from the Florida governor. It's a long shot, but with 20 years behind you with no further brush with the law,, you would have a better chance than many. You can read about it and get the forms to fill out here.
The office of Executive Clemency does the screening for the governor.
Any person who knowingly provides false information on such sworn statement to the court commits a felony of the third degree, punishable as provided in s. 775.082, s. 775.083, or s. 775.084.