What is the best way to write a regular expression?

Question

PHP

Hello.
There is the following line

"$cond($eq($HND,1),0.85*($m1*1.2*1.03*$MWS/100)+0.03*($MW+$mw)/2-1,1.2*($m1*1.2*1.03*$MWS/100)+0.03*($MW+$mw)/2+1)"

which is inside the text.
I need to correctly compose an expression in order to get the following values ​​(there may be different constructions inside "", but the essence of the regular expression is the same)

Array(
        [0] => array(
                          [0] => '$cond',
                          [1] => '$eq($HND,1)',
                          [2] => '0.85*($m1*1.2*1.03*$MWS/100)+0.03*($MW+$mw)/2-1,1.2*($m1*1.2*1.03*$MWS/100)+0.03*($MW+$mw)/2+1'
                          ),
        [1] => array(
                           [0] => '$eq',
                           [1] => '$HND',
                           [2] => '1'
                          )

Roughly speaking, to decompose the functions inside this construction into components

Answer 1

Considering that other functions can be arguments, there is little you can do here with regular expressions (by the way, in your example Array[0][2] is not correct, since, logically, the string
should have gone to Array[0][3 ] as the third argument of the function)
Such a problem could be solved by the following algorithm:
It can be implemented both with recursion and with a simple loop. It seems that he painted everything intelligibly and did not miss anything