The short answer is going to be, "Yes, that it helps rather than hurts to have an existing child support order from another place." The complications come in deciding (a) where that order came from, and (b) whether there are any problems in the original order. Your question aims at bringing an order “to the United States.” We’ll start with this idea, and then move into what you might want to do, based on another assumption…that the original court still has jurisdiction and an interest in the case. You’ll want to update the order you have. One issue can be that you think the parent has moved to Louisiana. Even if you’re e not absolutely sure where the moving parent has gone to, Louisiana is a part of an 18-state partnership that actually searches for a parent’s location. This means they will help find a parent: http://www.dss.state.la.us/index.cfm?md=pagebuilder&tmp=home&pid=142.
 
In a real sense, you may not need to get a “new” order, but need to enforce the old one in a new place. To get that done in Louisiana, you’ll need to file a verified statement for registration of a foreign order of support. Here’s a case that you can also use to follow as a guideline, or to let a clerk in a New Orleans court understand what you’re looking for. http://caselaw.findlaw.com/la-court-of-appeal/1027609.html.
 
Enforcing A Foreign Support Order In the United States
 
Since you listed Louisiana as where you want to base your answer in, I’m assuming Louisiana is also the state where “the other parent” moved to. Above is a sample case where Louisiana won a case, where the state of Georgia tried to avoid enforcing an order from a Louisiana court. This should help convince Louisiana’s local child enforcement authority that the system works both ways…Louisiana will usually want to enforce valid foreign child support orders. This is where it’s possible that the parent who moved will argue there was  a problem with the original order. Many court systems, though, are going to be entitled to more or less the same treatment as US state courts. Each country’s different in enforcing support orders…. http://www.state.gov/documents/organization/86823.pdf . Also, you can write to the US HHS to ask…(Ask-OCS-L-Dom- Post@state.gov).Canada is a good example of a court system that’s commonly accepted as valid. Was the other parent served with the original order, for example? If there was a problem with service to them, and you have now located the other parent, you may need to “fix” these problems before enforcing a foreign judgment.
 
So if you are trying to avoid going into Louisiana court, contact Louisiana’s child support enforcement first:
 
http://dss.louisiana.gov/index.cfm?md=pagebuilder&tmp=home&pid=137.
 
Keep The Original Court Informed
 
One thing that won’t change, no matter what court you are in, is that a court that once had the power to issue a support order generally keeps a “continuing interest” in the well-being of the child. A parent who owes child support does not evade that duty just because they may not live in the jurisdiction of the court. While it’s not clear what country the order was from there will be the equivalent of a court clerk or administrator. If you can obtain information regarding the paying parent’s new job, assets (real estate, home, auto, banking), then you can also get a specific order against those assets. For example, most custody payments in Louisiana come from salary payment orders: here’s how to get it: http://www.dss.state.la.us/index.cfm?md=pagebuilder&tmp=home&pid=225.Have the court clerk (or whatever it may be called in your country) explain what forms you need to update your existing order to target what you know about the other parent’s assets. Many states will honor a foreign monetary judgment. The more specific the foreign support order is, the better the chances you have of getting it enforced, and not just getting a “new” support order in Louisiana.