Explicit type conversion functions

I need to convert a char value returned by the select query to number.

Select max(to_number(child_id))

from table . . ..

i don't know what function is used in Minisap for this conversion of character to Number. Remember i am using Minisap that is i think 46C or 46D.

I find out a function NUM(a) from SAP help portal but that doesnot work with the release i am using.

Can any body help me plz.

Regards

Zahid