Hi,
There is no OC function for creating a baseline based on ALS method so far.
However, to open Peak Analyzer as you mentioned, I think you could save the options as a theme first and then use pa X-Function to open the dialog.
1. Select Analysis: Peak and Baseline: Peak Analyzer to open dialog
2. Select Create Baseline, click Next button and select ALS as Baseline Mode
3. Click the black triangle button and select Save as “MyTheme”
4. Run LabTalk Script to open PA dialog with the options you specified
pa iy:=(1,2) smode:=0 theme:=MyTheme;
https://www.originlab.com/doc/X-Function/ref/pa
5. To execute LabTalk script in Origin C, you could use Origin C function: LT_execute
https://www.originlab.com/doc/OriginC/ref/LT_execute
Hope it helps.
Regards,
Yuki
OriginLab