I have a string field with mostly numeric values like `13.4`, but some have `13.4%`. I am trying to use the following expression to remove the `%` symbols and retain just the numeric values to convert the field to integer. 

Here is what I have so far in the expression definition of Cognos 8 Report Studio:

```
IF(POSITION('%' IN [FIELD1]) = NULL) THEN 
  /*** this captures rows with valid data **/
  ([FIELD1]) 
ELSE 
  /** trying to remove the % sign from rows with data like this 13.4% **/
  (SUBSTRING([FIELD1]), 1, POSITION('%' IN [FIELD1]))) 

```

Any hints/help is much appreciated.