First of all, the .cfg file goes in the cstrike\maps directory, not just cstrike.
The problem seems to lie in your origins - they just don't work. How did you go about getting them? Load up the map and type 'status' in the console. Then just write down the x, y, and z values and put them into your de_dust2_monster.cfg file. Here's what I used for de_dust2:
{
origin/-1368 -754 181
delay/10
monster/hgrunt
}
{
origin/198 -755 53
delay/10
monster/barney
}
This sets up two spawn points near the Terrorist spawn. Also, if you only plan to spawn one type of monster at a certain point, you only need one line telling it to do so. For example:
{
origin/-1368 -754 181
monster/hgrunt
monster/hgrunt
monster/hgrunt
}
is no different than just
{
origin/-1368 -754 181
monster/hgrunt
}
The number of lines you have calling the same monster just determine the probability of it spawning. So, the following will spawn an hgrunt 100% of the time:
{
origin/198 -755 53
monster/hgrunt
}
While this will give you a 75% chance of spawning an hgrunt and a 25% chance of spawning barney:
{
origin/198 -755 53
monster/hgrunt
monster/hgrunt
monster/hgrunt
monster/barney
}
Go ahead and make another .cfg file using the method of obtaining origins I told you about. Everything should work fine.