BZZ
I just give you an example of a dosbox.bat file that should offer data disk selection, but never tested.
Parallel to this, all the lines in the [autoexec] section of dosbox.cfg must be commented.
@echo off
:menu
cls
echo.
echo.
echo.
echo.
echo.
echo WIN95 Collections
echo.
echo 1 = Collection 1 - Data1.img
echo 2 = Collection 2 - Data2.img
echo 3 = Collection 3 - Data3.img
echo.
echo 4 = Quit
echo.
choice /n /c:1234 Make a selection:
if errorlevel ==4 goto leave
if errorlevel ==3 goto c3
if errorlevel ==2 goto c2
if errorlevel ==1 goto c1
goto end
:c1
imgmount 2 win95.img -size 512,63,16,520 -t hdd -fs none
imgmount 3 data1.img -size 512,63,64,1023 -t hdd -fs none
boot -l c
goto menu
:c2
imgmount 2 win95.img -size 512,63,16,520 -t hdd -fs none
imgmount 3 data2.img -size 512,63,64,1023 -t hdd -fs none
boot -l c
goto menu
:c3
imgmount 2 win95.img -size 512,63,16,520 -t hdd -fs none
imgmount 3 data3.img -size 512,63,64,1023 -t hdd -fs none
boot -l c
goto menu
:leave
exit
:end