there is a fundemental problem here, whichever way you look at it the gold effect you actually want [as opposed to a monochrome 'gold'] is a bitmap texture - sure you can make a monochrome vector of the text, but when you convert that to 3D in xara designer you are going to want to manipulate that in 3D [or there is not much point in doing it] and the texture will not automatically follow the 3D shape in xara designer - it might if you use xara 3D program, depends what you actually want to end up with

tracing the gold effect itself is one option [photographic trace] but it is 'untidy' due to the number of shapes and slow to work with, but here's an example:

goldtext test.xar

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no time to try to clean it up, as you can see, for example by the way the extrusion spreads out - if you were to go this way an inkscape colour trace might be better because it has fewer shapes, but to be honest, if you are going to make a habit of this I think you should be looking at illustrator, or an animation program, or at the very least Xara 3D...