Assuming you have an Excel file with columns for the leader text and for the x,y positions of the start and end of the leaders you can create a VLISP statement that you can copy and paste into the command line in AutoCAD.
For example, given this Excel layout:

You can copy-down this expression in cell F4:
=CONCATENATE("(command ",CHAR(34),"_MLEADER",CHAR(34)," ",CHAR(34),B4,",",C4,CHAR(34)," ",CHAR(34),D4,",",E4,CHAR(34)," ",CHAR(34),A4,CHAR(34),")")
Note that ASCII character 34 (quote) is used in the concatenate command to generate the quotes needed in the VLISP statement to distinguish from the quotes that are needed in the Excel concatenate function.
I used x and y offset values in cells A1 and A2 to calculate the leader end points that are in columns D and E.
You can copy and paste the contents of column F (F4:F6) into the AutoCAD command prompt to generate the series of leaders or you can use it to create a .scr file.
lee.minardi