Help on moving files with MSI

I am currently rebuilding our old WiseScript installation into a more modern MSI installation.
I at the end of the MSI installation I want to move some user created files from a directory to another depending on if our old installation program has been detected. So I have created a DLL file with some custom actions that finds the old directories and sets an MSI property with the folder containing the certain files I want to move.

Now to my problem:
To get all this going I created a new record in the "Movefile" table with the following values:
FileKey: MoveSeqFiles
Component_:
SourceName: *.seq
DestName:
SourceFolder: WPM_OLDMACPATH
DestFolder: WPM_SEQFILES_PATH
Options: 0

I tried to not set a "component_" value, but in that case the entire record was removed when I compiled the MSI. I then created a component under the "Component" table like this:
Component: MoveSeqFiles
ComponentId: {685A18D8-5787-4D0D-B68B-7AC6069AF425}
Directory_:
Attributes: 0
Condition:
KeyPath:

Now what the heck should I put in the "Directory_" field in the compnent table if I just want to perform this move and the Source directory is not even known at compile time? Thats my first question.
It seems I need to have a component entry to make the movefile to perform at all.
Am I doing the right thing in the first place? I mean, I just want to move some files here where the Source directory is placed in a property.

Regards
Magnus