Make this change to THISFORMSET.acCommands[]:

save_FridgLabel(lcIndex, 20, 10)
save_FridgLabel(lcIndex, 20, 5)
save_FridgLabel(lcIndex, 10, 10)
etc.

And try this:

FOR i = THISFORMSET.nStart TO THISFORMSET.nEnd
	FOR lnPosCommands = 1 TO ALEN(THISFORMSET.acCommands)

		lcIndex = TRANSFORM(i) && <<<<<<<<<<< NEW

		EVALUATE(THISFORMSET.acCommands(lnPosCommands))
	ENDFOR
	=MESSAGEBOX(VARTYPE(i)) &&<= displays 'C'
	*i = Val(i)
ENDFOR

>>You don't need macro substitution:
>>
>>

>>FOR i = THISFORMSET.nStart TO THISFORMSET.nEnd
>>	FOR lnPosCommands = 1 TO ALEN(THISFORMSET.acCommands)
>>*		lcCommand = THISFORMSET.acCommands(lnPosCommands)
>>*		&lcCommand
>>		EVALUATE(THISFORMSET.acCommands(lnPosCommands))
>>	ENDFOR
>>	=MESSAGEBOX(VARTYPE(i)) &&<= displays 'C'
>>	*i = Val(i)
>>ENDFOR
>>

>>
>>Check THISFORMSET.acCommands[], may have "i = ALLTRIM(STR(i))"
>>
>>Is i being passed by reference to any of the functions?
>
>i is never passed by reference (no @) and all the commands in acCommands are basically the same function call with different parameters (only the last two change):
>

>save_FridgLabel(ALLTRIM(STR(i)), 20, 10)
>save_FridgLabel(ALLTRIM(STR(i)), 20, 5)
>save_FridgLabel(ALLTRIM(STR(i)), 10, 10)

>etc.
>
>The function save_FridgLabel is in a DLL and is defined as follows:
>

>extern "C" __declspec(dllexport) LONG save_FridgLabel(LPSTR, LONG, LONG);
>

>
>Is it because of the DLL function (even though the LPSTR seems appropriate)?
>
>Stephane.
>
>
>P.S. The first parameter of the function is never used a left operand in the C function.