Convert a collection to comma separated or colon separated string

 Lets assume [colName] is your collection, [column] is your column & you want to convert it into a string with items in the Title column comma or ';' separated.

 For Ex. you have a collection with emails in the Email column & you want to convert it into a string for sending emails to all who are there in the collection.

Use below formula:

Mid(Concat([colName], ";" & [column]), 2, 1000)

Use ", " for separating using comma.

Mid(Concat([colName], ", " & [column]), 2, 1000)