Need help to calculate Numbers

Can any one help me to modify the below pasted codes? since that lisp which i got from other site...but i would like to modify as per my requirement...I am not familiar with lisp programs...pls some one help me..

currently this lisp will add numbers from first numbers only in each text selection (ie. 2, 3)...But i would like to change as below..

As per snap shot...Total = ((2*4)+(3*5)+(5*6)) = 53

the code is

 (Defun c:add()
 (setq sset(Ssget '(( 0 . "TEXT")))
Index 0
val 0)
 (repeat (sslength sset)
   (setq strend(- (strlen (cdr(Assoc 1 (entget(ssname sset index)))))4)	  
   	  cval (substr (cdr(Assoc 1 (entget(ssname sset index)))) 1 strend)
  cval1(atoi cval)
   	  val(+ val cval1))
   (Setq index (+ 1 index)))
 (alert (Strcat "Total " (rtos val 2 0) " No's found")))

That's a very specific set of circumstances.

Are the values always the 1st and 3rd characters

Are they always numeric values

etc...

-David

Thanks David Bethel...

Are the values always the 1st and 3rd characters

Yes...1st & 3rd characters only...but 3rd character will be one or two digits (Ex. 33, 43)

Are they always numeric values

Yes..all are always Numeric values only

Try this

(defun c:add (/ cval cval1 index l ss strend val)
 (setq ss    (ssget '(( 0 . "text")))
l     (sslength ss)
index 0
val   0)
 (repeat l
   (setq strend (cdr(assoc 1 (entget(ssname ss index))))	  
   	  cval   (atoi (substr strend 3))
  cval1  (atoi strend)
   	  val    (+ val (* cval cval1))
         index  (+ 1 index)))
 (alert (strcat "total = " (rtos val 2 0))))

Maybe :

[b][color=BLACK]([/color][/b]defun c:sumtext [b][color=FUCHSIA]([/color][/b]/ ss i en tv i1 i2 vl sum[b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]and [b][color=NAVY]([/color][/b]setq ss [b][color=MAROON]([/color][/b]ssget '[b][color=GREEN]([/color][/b][b][color=BLUE]([/color][/b]0 . [color=#2f4f4f]"TEXT"[/color][b][color=BLUE])[/color][/b][b][color=BLUE]([/color][/b]1 . [color=#2f4f4f]"#?#*"[/color][b][color=BLUE])[/color][/b][b][color=GREEN])[/color][/b][b][color=MAROON])[/color][/b][b][color=NAVY])[/color][/b]
      [b][color=NAVY]([/color][/b]setq i 0[b][color=NAVY])[/color][/b]
      [b][color=NAVY]([/color][/b]while [b][color=MAROON]([/color][/b]setq en [b][color=GREEN]([/color][/b]ssname ss i[b][color=GREEN])[/color][/b][b][color=MAROON])[/color][/b]
             [b][color=MAROON]([/color][/b]setq tv [b][color=GREEN]([/color][/b]cdr [b][color=BLUE]([/color][/b]assoc 1 [b][color=RED]([/color][/b]entget en[b][color=RED])[/color][/b][b][color=BLUE])[/color][/b][b][color=GREEN])[/color][/b]
                   i1 [b][color=GREEN]([/color][/b]atoi [b][color=BLUE]([/color][/b]substr tv 1 1[b][color=BLUE])[/color][/b][b][color=GREEN])[/color][/b]
                   i2 [b][color=GREEN]([/color][/b]if [b][color=BLUE]([/color][/b]wcmatch [b][color=RED]([/color][/b]substr tv 4 1[b][color=RED])[/color][/b] [color=#2f4f4f]"#"[/color][b][color=BLUE])[/color][/b]
                          [b][color=BLUE]([/color][/b]atoi [b][color=RED]([/color][/b]substr tv 3 2[b][color=RED])[/color][/b][b][color=BLUE])[/color][/b]
                          [b][color=BLUE]([/color][/b]atoi [b][color=RED]([/color][/b]substr tv 3 1[b][color=RED])[/color][/b][b][color=BLUE])[/color][/b][b][color=GREEN])[/color][/b]
                   vl [b][color=GREEN]([/color][/b]cons [b][color=BLUE]([/color][/b]* i1 i2[b][color=BLUE])[/color][/b] vl[b][color=GREEN])[/color][/b][b][color=MAROON])[/color][/b]
             [b][color=MAROON]([/color][/b]setq i [b][color=GREEN]([/color][/b]1+ i[b][color=GREEN])[/color][/b][b][color=MAROON])[/color][/b][b][color=NAVY])[/color][/b]
        [b][color=NAVY]([/color][/b]setq sum [b][color=MAROON]([/color][/b]apply '+ vl[b][color=MAROON])[/color][/b][b][color=NAVY])[/color][/b][b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]prin1 sum[b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]prin1[b][color=FUCHSIA])[/color][/b][b][color=BLACK])[/color][/b]

-David

This will allow for any number of digits either side of the 'x':

(defun c:addit ( / a b c d )
   (if (setq a (ssget '((0 . "TEXT") (1 . "#*[xX]#*"))))
       (repeat (setq b (sslength a))
           (setq c (strcase (cdr (assoc 1 (entget (ssname a (setq b (1- b)))))))
                 d (cons (* (atoi c) (atoi (substr c (+ 2 (vl-string-position 88 c))))) d)
           )
       )
   )
   (print (apply '+ d))
   (princ)
)

Thanks paulmcz, David Bethel & Lee Mac.. Its working fine...thanks a lot..