Could anyone please give me solution regarding large decimal number values stori

Could anyone please give me solution regarding large decimal number values storing and validations on it,

I'm trying to give more than 15 digits number with two decimal digits,but it rounds that number to the nearest value and resetting the decimals to 0's.
Example:99999999999999999.99

I used fixed(), text() function to get the solution for this problem, but these also gave same behaviour.
Example: 1. fixed(
                              ri!num,
                              2,
                              true()
                              )

          2. text(ri!num,"##################.##")

Apart from this, in rule inputs and pv's number(decimal) values was stored in exponential form if number is more than 10 digits ex: 1e+15.
I'm using len() to get length of the value, it reruns improper value Ex:5 because Rule input and Process variable storing exponential value.
and If I tried with len(fixed()), it was returning value more than length of the number specified....

OriginalPostID-124740

OriginalPostID-124740