This is the code in the CS_Weapon.xml file (found in the folder of your aircraft) which sets up the rockets:

<Weapon>
           <Gun>Hydra 70</Gun>
           <Shell>Hydra 70</Shell>
           <Unlimited>0</Unlimited>
           <Station name="LeftWingOuter" params="-5,0,0,0,-0.039,0,30" />
           <Station name="LeftWingInner" params="-2,0,0,0,-0.039,0,30" />
           <Station name="RightWingInner" params="2,0,0,0,-0.039,0,30" />
           <Station name="RightWingOuter" params="5,0,0,0,-0.039,0,30" />
           <Mode name="AUTO" setshots="0" shotrate="30" sequence="1,2,3,4" reset="0" />
           <Mode name="X4" setshots="4" shotrate="30" sequence="1,2,3,4" reset="0" />
           <Mode name="1+4" setshots="2" shotrate="15" sequence="1,4" reset="0" />
           <Mode name="2+3" setshots="2" shotrate="15" sequence="2,3" reset="0" />
           <DefaultMode>AUTO</DefaultMode>
       </Weapon>
       <Weapon>
           <Gun>Zuni127</Gun>
           <Shell>Zuni127</Shell>
           <Unlimited>0</Unlimited>
           <Station name="LeftWingOuter" params="-5,0,0,0,-0.039,0,4" />
           <Station name="LeftWingInner" params="-2,0,0,0,-0.039,0,4" />
           <Station name="RightWingInner" params="2,0,0,0,-0.039,0,4" />
           <Station name="RightWingOuter" params="5,0,0,0,-0.039,0,4" />
           <Mode name="AUTO" setshots="4" shotrate="8" sequence="1,2,3,4" reset="0" />
           <Mode name="1+4" setshots="2" shotrate="8" sequence="1,4" reset="0" />
           <Mode name="2+3" setshots="2" shotrate="8" sequence="2,3" reset="0" />
           <Mode name="SINGL" setshots="1" shotrate="32" sequence="1,2,3,4" reset="0" />
           <DefaultMode>AUTO</DefaultMode>
       </Weapon>


You see those Station name bits? That's the start position. Now, I'm not sure, but the first three parameters (e.g. for RightWingOuter they are 5,0,0) are the X, Y, Z coordinates. Make the the third number (the Z coordinate) lower and the rocket should fire farther down. If this doesn't work, post and I'll look more into it. 

Maybe this is a better example because it has a guide to what the numbers refer to when changing the actual location of the weapons:

<Weapon>
  <!-- weapon sub-type section. unlimited number of -->
  <Gun>M60C</Gun>
  <!-- weapon sub-type name. must match GunInfo>Gun>Name -->
  <Shell>M60C Bullet</Shell>
  <!-- shell name. must match GunInfo>Shell>Name -->
  <Unlimited>1</Unlimited>
  <!-- unlimited ammo fire. 1-yes, 0-no -->
  <Station name="Nose" params="0,9,0,0,-0.039,0,200" />
  <!-- Station position (x,y,z) meters, angle of incidence, ammo units quantity -->
  <Mode name="AUTO" shotrate="10" setshots="0" sequence="1" />
  <!-- fire mode section. unlimited number of. name= dispayed on HUD in weapon info string. -->
  <Mode name="X3" shotrate="10" setshots="3" sequence="1" />
  <Mode name="SINGL" shotrate="10" setshots="1" sequence="1" />
  <DefaultMode>AUTO</DefaultMode>
  <!-- default fire mode. Any from the list above  -->
</Weapon>

Mark

That's odd. You didn't change anything other than the position, did you? (Oh, thanks Mark, for providing the example, that was probably much more helpful than my explanation  )

Perhaps the smoke effect needs to be moved downwards too? I'll look in the xml file later and see if I can find anything.
I can't seem to figure out what your 2) means (the Google Translation is poor). What language are you translating from?  

boeing247 said - Perhaps the smoke effect needs to be moved downwards too?
No you don't. The smoke effects is tied to the rockets. So if you lower the rockets, the smoke lower as well.

florence said - I hope I was clear SORRY FOR MY ENGLISH
You are doing good with your English so far, so we will do our best to help you get the rockets in the right place on the wings.
I'm soryy, but I do not own the Lotus Simulations L-39 Albatross. So it is hard for me to show what to change the numbers to in CSWeapon.xml

Mark

Ciao il mio codice sorgente del razzo Hydra e' perfettamente uguale a quello che mi hai postato tu .
Il vero problema e' che appena modifico il file CS_Weapon .xml scoppia un casino non capisco perche'
Grazie

It seems incredible that the Captain Sim can not find a solution to this problem
no one can explain that I have to change the parameter to fire rockets under the wings amazing!!
MANY THANKS to BOEING247 only one who has tried!

Hi David.

Can you copy the changes you made in the CSWeapon.xml and paste them in here so we can see if there is a mistake that is causing this problem.

Mark