Multiple groups in Moodle linked course.

Hi, the issue is this. We have some students we call "fast track students". They are attending more then one session per week (For example Weekday group and weekend group) so they need to be enrolled in two groups. This can be done in Axcelerate but when the student is added to the second group Axcelerate will not add them as they are already enrolled in the first group so the second group enrolment is ignored. This causes an issue particularly if the end dates are different for the second group and the first group is finished. Question: How can we get Axcelerate to add students to more another group when the student is already linked to a group Moodle?