Embed current date into URL (matlab)

I want to download a file from the following link: https://nomads.ncep.noaa.gov/cgi-bin/filter_gfs_0p25_1hr.pl?file=gfs.t06z.pgrb2.0p25.f039&lev_surface=on&var_CAPE=on&leftlon=0&rightlon=360&toplat=90&bottomlat=-90&dir=%2Fgfs.2019060206

How can I embded the current date, run time and forecast hour in the URL after predefining them? I have tried the following but it doesn't work:

myrun = 00; % 00 06 12 18
mydate = 20190603; % yearmonthday
myforecasthour = 039; % t + number of hours ahead
fullURL=['https://nomads.ncep.noaa.gov/cgi-bin/filter_gfs_0p25_1hr.pl?file=gfs.t',num2str(myrun,'%02.f'),'z.pgrb2.0p25.f',num2str(myforecasthour,'%03.f'),'&lev_surface=on&var_CAPE=on&leftlon=0&rightlon=360&toplat=90&bottomlat=-90&dir=%2Fgfs.',num2str(mydate)'];
filename = 'cape_test';
urlwrite(fullURL,filename);