IIF statement retuns a type mismatch error - but only for a certain format of data

[kontorirott]

So here is a deal. I have a long list of articles, all imported into Access from TXT file, field is a text. A large portion of them begins with four zeros, and I need to filter them and convert into 6 signs codes, the latter 6 signs. there are also lots of 10 signs codes, that must remain as they are. Now what had put me in deadlock is that IIF statement selects easily the rows beginning with "0000" and produces Right(([field]);6), or six last signs from all types of articles (as positive statement criteria): all numeric, combined alpha-numeric, all alphabetical (100% alphabetical field are filtered with negative criteria, which is just reproducing the whole field) - the only exception is alpha-numeric combinations that begin with a letter. Those query rows produce an type mismatch error, like when you are entering a number in a text field. But if it is a text source, both for numbers and alpha-numeric combinations, and it is okay to select certain fields from this text string - why am I getting an error only for alpha-numeric combinations, beginning with a letter? Why is this happening and how can I get rid of this? so it cannot be alpha instead of number or vice versa, it cannot be alpha/number instead of boolean - it must be something else. any ideas, please?

[June7]

Need code to analyse. Post the IIf expression. Post the entire SQL statement. If you want, provide db for analysis. Follow instructions at bottom of my post.

[kontorirott]

Hahaa, got it. me stupid. here's the IIF statement:

Short-long_division: IIf(Left(([BR_new]![Part number]);4)=0;Right(([BR_new]![Part number]);6);[BR_new]![Part number])

and the fault was Numeric field in the expression, I have changed =0 to ="0000" and it was working as I needed it to. Thank you everybody!