New Post: Comma/Semicolon formula problem

I have a problem with a formula containing IF function. The formula defined directly in Excel spreadsheet looks like this:

=IF(ISERR(M2/L2);"";M2/L2)

The semicolon here comes from the regional settings (comma is reserved for the decimal point).
The problem appears when I want to implement the formula using NPOI library. If I use it as above NPOI warns me about the incompleted formula (missing comma). If I replace semicolons with commas NPOI throws a low level exception with "too far" message. Is there any proper solution here?