Subject Re: FB engine not finding F_LEFT
Thank you Set, Mark and Maya. I think I see my error and will test it tomorrow. 
On the network where F_LEFT worked I had installed FreeUDFLib.DLL long ago.
On the remote laptop where if failed I did not install FreeUDFLib.dll
Using Substring(..) or LEFT(..) is better as they require no installation and thereby reduce chances for error.

I tried Left( ) and it failed ... then I saw I had not replaced all 7 instances of F_LEFT() with LEFT(). 
Another error.
Many thanks.