Should you wish to time align data from different files and formats, it will be necessary to do this in an external program, such as Excel. You will therefore need to export the LabChart data as text (File>Export>LabChart Text File) and then open in the external program. You can then combine data from other sources. Each channel of data should be in a separate column and aligned by the sample time or suitable sample rate in the same row.
To complete save the document as a text file (generally TAB delimited works well) which can then be opened by LabChart (File>open> change file type to text file). Channels should appear time aligned as required.