Can we add text to link at any position in goxam?

Yes. The default is to put any child of a LinkPanel at the middle of the link.

But you can set various attached properties to control exactly where to arrange it.
Read about setting go:LinkPanel.Index, go:LinkPanel.Fraction, go:LinkPanel.Offset, go:LinkPanel.Alignment, and go:LinkPanel.Orientation in the GoXamIntro.pdf section about “Data Templates for Links”.