Can I create a gradient on a color matte in PP?

In PS you can drag a gradient slider acoss a color matte to gradually reveal what's underneith. I would like to do the same thing in PP to reveal text on a color matte over a moving image. I've searched Google and found the Ramp and 4-Color Gradient but I can't make them do what I want:

I would like a color gradent to appear over half my clip, not the whole clip, and transition from that middle point from 10%-50%. (So across the whole screen 50% of the image would be unafected, then at the middle point [of the clip] the gradient starts from 10% - 50% across the other half of the screen.)

What I can do is place a Color Matte over the clip, move it to the half-way marker and fade it. Above that layer is my text layer. The effect is okay but I would rather have a soft transition instead of a hard line down the middle. Is this possible in PP? 

I tried moving the position of the Ramp but the first color can not be transparent, which is what I need for Ramp to work. 

Is what I want to do possible in PP or would I need to move over to AE?