Adding a white layer only on text?

[Chromatic]

So I have a transparent background with text that says "Hobby Forum".

This text has a blue and black gradient over it, but I want it to have that half-oval shape of white on it to make it lighter on top and the regular gradient on the bottom.

How do i do that without having the white on the transparent background.

Hope you understand what I mean.

 

[SeniorS]

Didn't quit understand but if you want to change letters gradient then:
1. take magic wand (W) make tolerance - 0, Contiguous - uncheck.
2. click somewhere on transparent.
3. invert selection (SHIFT+CTRL+L).
4. now you can fill it with gradient you want.

 

[Chromatic]

So i have text on a transparent background that says Hobby Forum.

The text has a gradient on it already.

I want half of the text in an oval shape to have a white overlay on it to make it Lighter than the other half of the text. How do i do this without making white on the transparent bg?

 

[SeniorS]

Select whole text as i said. Inverse selection. Use it as layer mask (layer/layer mask/reveal selection). Click on layer in layer panell.
Now paint, gradient or else with some transparency and blending modes (experiment).