Have you tried a program like [url=]http://www.xpadder.com/[/url]?

Same problem here.
GOG support refuses to even reply.
Here's what I'm doing: buying a PCI sound card with the MIDI/gameport 15 pin DB connector and buying an older analog joystick to plug into the soundcard.
Hope this will work, o/w Megarace is no fun on mouse and MR2 is IMPOSSIBLE without it. Even with the joystick support in MR2, the control is so bad one can't even play it.

Just installed the Inland sound card (PCI) with a gameport and bought an old analog Gravis joystick. Istalled and STILL no joystick. Hardware device manager says "not connected" under the joystick, and no amount of sound card drivers will change this......ARGHHH

SO far have rewritten the joystick commands in DosBox, changed out soundcard/gameport twice, tried both analog and USB joystick ans.....NOTHING!
Very hard to play without joystick, and no one seems to know how to make it work....frustrating!!!

Have now used 3 soundcards with gameport....no joy
2 joysticks....USB and 15 pin....no joy
Modified the joysitck file in DOSbox....no joy
Used original CDROM to try and bypass this....no joy
GOG.com support says they only tried it with keyboard....but are trying to get a fix for us.
Last move will be to add a stick on XP's list and see if it'll run.....doubt it, but will post results.

New (old!) joystick that XP lists as compatible.....no joy
I give up.
Hopefully, GOG can fix this. THe group at DOSbox have been unable to help either.

Did you try xpadder? I know I linked the pay for version which I didn't realise it was pay for at the time of me linking it, but if you google for it you can find older free versions of the program. It should just emulate keyboard strokes onto your game pad, so any input through the controller the game should think its a mouse or keyboard.

I tried Megarace 2 with joy some years ago. But too hard to use, car always sliding with this method of control.

The solution is here, as there are many posts with this problem I posted in another topic:

http://www.gog.com/en/forum/megarace_series/megarace_1_joystick_fix

I'm using JoytoKey and it works great.

Actually, it does recognize it, kinda. I just tried it myself. I have trouble navigating menus with the controller, so I use the keyboard for that. During the actually races though, use the left stick to drive and steer and A to shoot.
I can't, however, get the right calibration for Megarace 2.