strripos
Find the position of the last occurrence of a case-insensitive substring in a string
[...] = optional ... = your value
[var $... = ]call strripos $haystack=…;$needle=…[;$offset=…]
Notes
negative $offset values count from the end of $haystack
positive $offset values count from the start of $haystack
Example code
Example output
Reloadhaystack = abcdefghijklmabcdefghijklm
needle = CDE
offset = 0
position = 15
haystack = abcdefghijklmabcdefghijklm
needle = CDE
offset = -12
position= 2