cant use function cmplx

Hi.
I cant use the cmplx function. I just created three function with the same number of points which i called aaa, bbb and ccc
then

ccc=cmplx(aaa,bbb)

but it tells me back:"function not available for this number type" (????)
any help?
cheers
You must use /C when declaring a complex variable:
Variable aaa=1, bbb=2
Variable/C ccc = cmplx(aaa,bbb)