The addition of the collection company is secondary to an assignment (this is quite common), there probably isn't anything that you can do to contest the motion (there isn't any basis to do so). You should have also been served with an "assignment of judgment" noting that the original judgment creditor is assigning their rights to the collection agency.
The creditor is not gaining any additional rights against you (you are not any worse off than you were before, it simply means that a new creditor is going to be enforcing the debt).
But if the creditor is attempting to collect on a debt that was already enforced, or is trying to assert rights that some other creditor is already asserting (we sometimes see this - but it is very, very rare), it is fraudulent, and you can contest the amendment of the caption on that basis. To determine if this is the case - contact the original creditor in writing and confirm whether or not they are assigning the judgment, AND, review the court papers (the "Register of Actions") for your case, to determine if an assignment of the judgment was entered. If it was not, you can file an opposition to the current motion to amend caption based on a failure to file a proper assignment of judgment. (I advise contacting the original judgment creditor first because if this was the intent and they simply failed to do so, you will have spent a lot of time and money opposing this motion and they will simply file the assignment, then file a second motion to amend - it is usually best to deal with these issues by letter rather than by motion if possible).
But if the motion is being made simply to enter a bona fide collection agency's name (who is taking the judgment in an assignment), so that they can enforce the judgment in their own name (such as placing liens in particular, but also: getting garnishments, bank levies, etc. in their name) there is nothing to contest.