welcome to "Open Savoir-Faire and Open Innovation on Linkedin and Le Cercle".
Started in 2010 when the concept of MOOC did not exist, this site shows that experience and practice is key with online teaching.
Before engaging a third party community manager, you might find prudent to test his skills in an open social network such as LinkedIn or Viadeo.
Check also his/her writing skills by having a look on his/her articles.
If the articles are published on an open media (e.g. a media that allows comments) and that there are some debates, all the best !
An alternate solution is to recruit a junior professional and take the opportunity to have in 24 months time frame a confirmed employee with double skills : the understanding of your business and community management capabilities aligned to your corporate culture.