conversion of digital pin to analog

Projects Programming
1

How Can I convert a digital pin to analog?I need more than 6 analog pins in my project.

2

Get a Mega.

3

How Can I convert a digital pin to analog?

You can't

I need more than 6 analog pins in my project.

How many, and do you mean analogue in or PWM out ?
The Arduino Micro has 7 PWM outputs and 12 analogue inputs.

4

Can also easily add an SPI interfaced MCP3208 for 8 more channels of 12-bt ADC Data. Or two, for 16 channels.
There are 8 and 10 bit versions also.
http://www.digikey.com/product-search/en/integrated-circuits-ics/data-acquisition-analog-to-digital-converters-adc/2556291?k=MCP3208
$3.40 plus a couple capacitors is way less then jumping up to a Mega.