You can choose "Manual" handicaps and enter them yourself.

You need to create a list of players and handicaps, one name per line, percentage and cut and paste to Manual box. If cut and paste from spreadsheet, can be a "Tab" separator. e.g.

Alan Smith,5.17
John Smith, -0.2

Any players for whom no handicap has been entered will be given a default handicap .

For each result in the competition, the result is taken and the handicap for each player is added together and averaged and applied to the result.

Normally Handicaps are applied to each result, but there are some circumstances, where you might just want to apply the Handicap to the Total. i.e. simply drop a player down -10 points.