You should be able to use AME (Adobe Media Encoder) to re-Encode you MOV file (if you have the CODEC, used in that MOV file properly installed, and it's one that AME can use) to MP4. To alter the File Size, you will need to reduce the Bit-Rate, which WILL affect the quality. Only you can judge whether that quality hit is acceptable.
What is limiting your File Size to 75MB?
Below are links to find out what is inside your MOV files... but, as a GUESS, your MOV file is "something like" the DV AVI files I use on Windows, which is about 13Gig per hour of video
When you export to MP4 you are "most likely" using options to create a HIGHLY compressed file, where much of the original information is removed exactly to create small sizes
Read Bill Hunt on a file type as WRAPPER http://forums.adobe.com/thread/440037
What is a CODEC... a Primer http://forums.adobe.com/thread/546811
What CODEC is INSIDE that file? http://forums.adobe.com/thread/440037
Report back with the codec details of your file, use the programs below... a screen shot works well to SHOW people what you are doing
Or... are you asking how to do that MOV-to-MP4 conversion... not that you have done so and don't know what you did?
Are you trying to ask the same question you asked in http://forums.adobe.com/thread/1070393 about uploading to the Internet?
Here are some tutorials
A "crash course" http://forums.adobe.com/thread/761834
A Video Primer for Premiere http://forums.adobe.com/thread/498251
Premiere Tutorial http://forums.adobe.com/thread/424009
-and more from Kevin http://forums.adobe.com/message/4714153
Premiere Pro Wiki http://premierepro.wikia.com/wiki/Main_Page
Tutorial HD to SD w/CS4 http://bellunevideo.com/tutorials/CS4_HD2SD/CS4_HD2SD.html
Color correction http://forums.adobe.com/thread/892861
After Effects Tutorials http://www.videocopilot.net/
Surround Sound http://forums.adobe.com/thread/517372
Photo Scaling for Video http://forums.adobe.com/thread/450798
-Too Large May = Crash http://forums.adobe.com/thread/879967
-And another crash report http://forums.adobe.com/thread/973935
I suspect you are trying to create a Youtube file in MP4
Use the Youtube preset in AME and then follow Bill Hunts bit rate advice to control the file size.
Its a bit trial and error... but 1GB should come down 75mb with a BR setting of around 4- 6 mbps