I am using the xls2dta command to combine multiple Excel files, which seems like a nifty, parsimonious way to go about this sort of thing. I am having a few issues and I don't have the programming mind to self-solve said issues with the manual. Hence, this post. My code goes like this

clear
cd "~/mychosendirectory"
xls2dta, save(combined.dta) importopts(firstrow) : append using .
use combined
Question 1: Is there a way to do this w/o saving a .dta file? This creates problems when I rerun my .do file since there will be an existing file saved in the directory.

Additionally, after I run this command I get this output:

. xls2dta, save(combined.dta) importopts(firstrow) : append using .
(13 vars, 11 obs)
(13 vars, 16 obs)
(10 vars, 11 obs)
(13 vars, 2 obs)
(13 vars, 2 obs)
(8 vars, 8 obs)
(13 vars, 4 obs)
file combined.dta saved
There is an issue with the file that only had 8 variables added since this file has 10 variables. This is the only file that didn't append completely. Any ideas what could be going on with that?

Thanks for any help, and apologies in advance if I (a) posted this in the wrong spot (b) didn't provide enough information, or (c) am not clear enough about what I'm asking... or anything else.