endless scaling and moving on the z axis

Hello,

I hope you all understand my english.
sorry if this is allready been posted, but i have some problems with using expressions.
I want a object to scale from zero to endlessly during the composition. And I also want to move the object forward endlessly on the Z axis.

I used this expressions:

Position:
temp = time*-200;

[value[0], value[1], temp]

Scale:

temp = time*300;
[temp,temp,temp]

No problems til now. But, I need the other layers to follow 10 frames later and start at the same startposition and the same scale value (zero) as the first layer.

I hope you get my problem and I one of you can help me fix this.