You can convert an .acp file to the .bld format. You can perform scanning for message changes and building database operations only on a loaded .bld file.
To convert to .bld file either
Double-click the .acp file in the tree view pane.
Right-click the file and click Convert to .bld.
Select the file, and click Convert to .bld on the toolbar.
Select the file, and then click Convert to .bld option on the Tools menu.