extracting substring from searchstring

Dear Team,

I have to extract substring from string and when extract is numeric I have to store it into another column

Table

column value

5 abc

5abc

abc

def 5 abc

def d abc

def d5 abc

Searchstring = “abc”, result = 2 letters before searchstring startposotion.

Table with expected results anways searching for “abc”

5 abc gives 5

5abc gives 5

abc gives missing, no result

def 5 abc gives 5

def d abc gives missing, because result is not numeric

def d5 abc gives missing, because result is not numeric

I tried with string manipulation node / string manipulation multiple columns, but unfortuanlety without success.

Any idea high appreciated.

BR,

Heinz