You need to look at it as to how you would otherwise manually dial the same number. How does one go about manually dialing a space? This is why skip the dial plan aspect still creates an error as there provider likely does not understand what a space is. The outbound number format must match that which the provider requires in order to pass the call along.
Do I take it that the number with a space is one that was stored from a received call and how the CID was displayed? Or, is this a number that is being pulled in from some other source?
Rightfully or wrongly, the expectation is that the source number is formatted correctly to begin with. Depending on the source, folks can input various digits or other to make the number more human friendly to read, 1-956-555-1212, 1.956.555.1212, etc., but these are not something that the provider can deal with so the call fails.
Depending upon what is being used for the source, if a PBX or provider, perhaps there is a provision to modify the incoming by looking at the request line rather than the TO. Perhaps there is a modification to the inbound string format that can be programmed into the inbound.
If a independent source, perhaps a script to create an XML file which would contain the needed number without the space along with the associated name. If names are to be included as a look-up then the number being presented to the phone must match exactly to pull the name.