You would also need to change
Dim rstna As ResumableSub = accountprocess(holdna)
to
Dim rstna As ResumableSub = accountprocess
Any "unused variable" warning can be cancelled by adding "'ignore" (that is, apostrophe and the word ignore) on the line where it is defined, eg.
Sub accountprocess (d As String) As ResumableSub 'ignore
The compiler will simply not issue a warning in this case.
You can also put the line
with the numbers of the warnings you want to ignore (31 & 34 in this case) in the Project Attributes region - again this just tells the compiler to ignore all warnings of these types.