vfs.file.regexp and float item

[mhoop]

Hello. In 4.0 I have built an item on a host with key vfs.file.regexp[filename, "A (\d+.\d+)",,,,\1] and cannot seem to get this to be acceptable as a float to allow graphing.
Data in file in format "A 15.5"
If I change Type of Information to Text I can get 15.5 but that is not graphable.
what is best practice on this?
thank you
murray