Button commands-"cd <new dir>" doesn't work if another drive

I have a button that runs a program on all files and folders in the current directory. It works fine as long as the current dir is on my c: drive, but not if it's on any other drive letter.
In the code for my button is

cd {sourcepath}

I know I need a command like

f:

(just the drive letter and colon)
How can I cut a path down to this?

Thanks in advance.

Admin: please feel free to remove this topic -- I found the answer, but it's not a Directory Opus question -- its DOS command:

cd /D {sourcepath} 

The /D switch.
Sorry about that.

have a good one.

You shouldn't need to CD to the current directory at all as buttons do that automatically.

For example, this as an MS-DOS type button will always display the current directory:

dir
pause