it should be something like this....

c_move(me,(vector((10 * time_step / 8),0,0)),nullvector,glide);
not all the brackets are necessary, but it's good practice to encapsulate or separate math operations.

there you would be moving forward(the actors "X")

a vec is using vector(x,y,z), you could add gravity by adjusting the "Z" paramater.
alternately it could be used to define color...
vector(red,green,blue), it really depends on the variable. I hope this makes sense and that it helps.