[NAV 2013] BOM Production Version Compare

on page Production BOM I have some Report code to Print the "Active Version" of my PN

IF ActiveVersionCode<>'' THEN
  BEGIN
    CLEAR(BOMVersion);
    BOMVersion.SETFILTER("Production BOM No.","No.");
    BOMVersion.SETFILTER("Version Code",ActiveVersionCode);
    BOMVersion.FIND('-');
    VersionBOMReport.SETTABLEVIEW(BOMVersion);
    VersionBOMReport.RUN;
  END
ELSE
  MESSAGE(txt50000, "No.");

I am now trying to create a similar "button" function that will link to a comparison report.

essentially:

From "BOM Version" being the "ActiveVersionCode" and the
"To BOM Version" should be set to "" ((actually two quotes not null)

(on another page the "TO BOM" will default to the currently open BOM and the FROM will be unspecified. just in case you were wondering.)

what is the best way to accomplish this in a single function in C/AL? copyfilters? any similar examples would be greatly appreciated.

thanks in advance